Arquivo da tag: Inteligência animal

When Whales and Humans Talk (Hakai Magazine)

Arctic people have been communicating with cetaceans for centuries—and scientists are finally taking note.

Tattooed Whale, 2016 by Tim Pitsiulak. Screen-print on Arches Cover Black. Reproduced with the permission of Dorset Fine ArtsApril 3rd, 2018

Harry Brower Sr. was lying in a hospital bed in Anchorage, Alaska, close to death, when he was visited by a baby whale.

Although Brower’s body remained in Anchorage, the young bowhead took him more than 1,000 kilometers north to Barrow (now Utqiaġvik), where Brower’s family lived. They traveled together through the town and past the indistinct edge where the tundra gives way to the Arctic Ocean. There, in the ice-blue underwater world, Brower saw Iñupiat hunters in a sealskin boat closing in on the calf’s mother.

Brower felt the shuddering harpoon enter the whale’s body. He looked at the faces of the men in the umiak, including those of his own sons. When he awoke in his hospital bed as if from a trance, he knew precisely which man had made the kill, how the whale had died, and whose ice cellar the meat was stored in. He turned out to be right on all three counts.

Brower lived six years after the episode, dying in 1992 at the age of 67. In his final years, he discussed what he had witnessed with Christian ministers and Utqiaġvik’s whaling captains. The conversations ultimately led him to hand down new rules to govern hunting female whales with offspring, meant to communicate respect to whales and signal that people were aware of their feelings and needs. “[The whale] talked to me,” Brower recalls in a collection of his stories, The Whales, They Give Themselves. “He told me all the stories about where they had all this trouble out there on the ice.”

Not long ago, non-Indigenous scientists might have dismissed Brower’s experience as a dream or the inchoate ramblings of a sick man. But he and other Iñupiat are part of a deep history of Arctic and subarctic peoples who believe humans and whales can talk and share a reciprocal relationship that goes far beyond that of predator and prey. Today, as Western scientists try to better understand Indigenous peoples’ relationships with animals—as well as animals’ own capacity for thoughts and feelings—such beliefs are gaining wider recognition, giving archaeologists a better understanding of ancient northern cultures.

“If you start looking at the relationship between humans and animals from the perspective that Indigenous people themselves may have had, it reveals a rich new universe,” says Matthew Betts, an archaeologist with the Canadian Museum of History who studies Paleo-Eskimo cultures in the Canadian Arctic. “What a beautiful way to view the world.”


It’s not clear exactly when people developed the technology that allowed them to begin hunting whales, but scholars generally believe Arctic whaling developed off the coast of Alaska sometime between 600 and 800 CE. For thousands of years before then, Arctic people survived by hunting seals, caribou, and walruses at the edge of the sea ice.

One such group, the Dorset—known in Inuit oral tradition as the Tunitwere rumored to have been so strong the men could outrun caribou and drag a 1,700-kilogram walrus across the ice. The women were said to have fermented raw seal meat against the warmth of their skin, leaving it in their pants for days at a time. But despite their legendary survival skills, the Tunit died out 1,000 years ago.An Inuit hunter sits on a whale that’s been hauled to shore for butchering in Point Hope, Alaska, in 1900. Photo by Hulton Deutsch/Getty Images

An Inuit hunter sits on a whale that’s been hauled to shore for butchering in Point Hope, Alaska, in 1900. Photo by Hulton Deutsch/Getty Images

One theory for their mysterious disappearance is that they were outcompeted by people who had begun to move east into the Canadian Arctic—migrants from Alaska who brought sealskin boats allowing them to push off from shore and hunt whales. Each spring, bowhead whales weighing up to 54,000 kilograms pass through the leads of water that open into the sea ice, and with skill and luck, the ancestors of today’s Inuit and Iñupiat people could spear a cetacean as it surfaced to breathe.

The advent of whaling changed the North. For the first time, hunters could bring in enough meat to feed an entire village. Permanent settlements began springing up in places like Utqiaġvik that were reliably visited by bowheads—places still inhabited today. Social organizations shifted as successful whale hunters amassed wealth, became captains, and positioned themselves at the top of a developing social hierarchy. Before long, the whale hunt became the center of cultural, spiritual, and day-to-day life, and whales the cornerstone of many Arctic and subarctic cosmologies.

When agricultural Europeans began visiting and writing about the North in the 10th century, they were mesmerized by Aboriginal peoples’ relationships with whales. Medieval literature depicted the Arctic as a land of malevolent “monstrous fishes” and people who could summon them to shore through magical powers and mumbled spells. Even as explorers and missionaries brought back straightforward accounts of how individual whaling cultures went about hunting, butchering, and sharing a whale, it was hard to shake the sense of mysticism. In 1938, American anthropologist Margaret Lantis analyzed these scattered ethnographic accounts and concluded that Iñupiat, Inuit, and other northern peoples belonged to a circumpolar “whale cult.”

Lantis found evidence of this in widespread taboos and rituals meant to cement the relationship between people and whales. In many places, a recently killed whale was given a drink of fresh water, a meal, and even traveling bags to ensure a safe journey back to its spiritual home. Individual whalers had their own songs to call the whales to them. Sometimes shamans performed religious ceremonies inside circles made of whale bones. Stashes of whaling amulets—an ambiguous word used to describe everything from carved, jewelry-like charms to feathers or skulls—were passed from father to son in whaling families.

To non-Indigenous observers, it was all so mysterious. So unknowable. And for archaeologists and biologists especially, it was at odds with Western scientific values, which prohibited anything that smacked of anthropomorphism.
A whaler waits for the bowhead whales from shore in Utqiaġvik, Alaska, during whaling season in the Chukchi Sea. Photo by Steven J. Kazlowski/Alamy Stock Photo

A whaler waits for the bowhead whales from shore in Utqiaġvik, Alaska, during whaling season in the Chukchi Sea. Photo by Steven J. Kazlowski/Alamy Stock Photo

In archaeology, such attitudes have limited our understanding of Arctic prehistory, says Erica Hill, a zooarchaeologist with the University of Alaska Southeast. Whaling amulets and bone circles were written off as ritualistic or supernatural with little exploration of what they actually meant to the people who created them. Instead, archaeologists who studied animal artifacts often focused on the tangible information they revealed about what ancient people ate, how many calories they consumed, and how they survived.

Hill is part of a burgeoning branch of archaeology that uses ethnographic accounts and oral histories to re-examine animal artifacts with fresh eyes—and interpret the past in new, non-Western ways. “I’m interested in this as part of our prehistory as humans,” Hill says, “but also in what it tells us about alternative ways of being.”


The idea that Indigenous people have spiritual relationships with animals is so well established in popular culture it’s cliché. Yet constricted by Western science and culture, few archaeologists have examined the record of human history with the perspective that animals feel emotions and can express those emotions to humans.

Hill’s interest in doing so was piqued in 2007, when she was excavating in Chukotka, Russia, just across the Bering Strait from Alaska. The site was estimated to be 1,000 to 2,000 years old, predating the dawn of whaling in the region, and was situated at the top of a large hill. As her team dug through the tundra, they uncovered six or seven intact walrus skulls deliberately arranged in a circle.

Like many archaeologists, Hill had been taught that ancient humans in harsh northern climates conserved calories and rarely expended energy doing things with no direct physical benefit. That people were hauling walrus skulls to a hilltop where there were plenty of similar-sized rocks for building seemed strange. “If you’ve ever picked up a walrus skull, they’re really, really heavy,” Hill says. So she started wondering: did the skulls serve a purpose that wasn’t strictly practical that justified the effort of carrying them uphill?

When Hill returned home, she began looking for other cases of “people doing funky stuff” with animal remains. There was no shortage of examples: shrines packed with sheep skulls, ceremonial burials of wolves and dogs, walrus-skull rings on both sides of the Bering Strait. To Hill, though, some of the most compelling artifacts came from whaling cultures.

Museum collections across North America, for instance, include a dazzling array of objects categorized as whaling amulets. From this grab bag, Hill identified 20 carved wooden objects. Many served as the seats of whaling boats. In the Iñupiaq language, they’re called either iktuġat or aqutim aksivautana, depending on dialect.

One in particular stands out. Hill was looking for Alaskan artifacts in a massive climate-controlled warehouse belonging to Smithsonian’s National Museum of Natural History in Washington, DC. The artifacts were housed in hundreds of floor-to-ceiling drawers, row after row of them, with little indication of what was inside. She pulled open one drawer and there it was—the perfect likeness of a bowhead whale staring back at her.

The object, likely from the late 19th century, probably functioned as a crosspiece. It was hewn from a hunk of driftwood into a crescent shape 21 centimeters long. Carved on one side was a bowhead, looking as it would look if you were gazing down on a whale from above, perhaps from a raven’s-eye perspective. A precious bead of obsidian was embedded in the blowhole. “It’s so elegant and simple but so completely whale,” Hill says. “It’s this perfect balance of minimalism and form.”

Sometime in the late 19th century, an Iñupiat carver fashioned this seat for an umiak out of driftwood, carving the likeness of a bowhead whale, its blowhole symbolized with a piece of obsidian. Photo by Department of Anthropology, Smithsonian Institute (Cat. A347918)Sometime in the late 19th century, an Iñupiaq carver fashioned this amulet for an umiak out of driftwood, carving the likeness of a bowhead whale, its blowhole symbolized with a piece of obsidian. As with other whaling amulets Erica Hill has examined, this object may have also functioned as part of the boat’s structure. Photo by Department of Anthropology, Smithsonian Institute (Cat. A347918)

Using Iñupiat oral histories and ethnographies recorded in the 19th and 20th centuries, Hill now knows that such amulets were meant to be placed in a boat with the likeness of the whale facing down, toward the ocean. The meticulously rendered art was thus meant not for humans, but for whales—to flatter them, Hill says, and call them to the hunters. “The idea is that the whale will be attracted to its own likeness, so obviously you want to depict the whale in the most positive way possible,” she explains.

Yupik stories from St. Lawrence Island tell of whales who might spend an hour swimming directly under an umiak, positioning themselves so they could check out the carvings and the men occupying the boat. If the umiak was clean, the carvings beautiful, and the men respectful, the whale might reposition itself to be harpooned. If the art portrayed the whale in an unflattering light or the boat was dirty, it indicated that the hunters were lazy and wouldn’t treat the whale’s body properly. Then the whale might swim away.

In “Sounding a Sea-Change: Acoustic Ecology and Arctic Ocean Governance” published in Thinking with Water, Shirley Roburn quotes Point Hope, Alaska, resident Kirk Oviok: “Like my aunt said, the whales have ears and are more like people,” he says. “The first batch of whales seen would show up to check which ones in the whaling crew would be more hospitable. … Then the whales would come back to their pack and tell them about the situation.”

The belief that whales have agency and can communicate their needs to people isn’t unique to the Arctic. Farther south, on Washington’s Olympic Peninsula and British Columbia’s Vancouver Island, Makah and Nuu-chah-nulth whalers observed eight months of rituals meant to communicate respect in the mysterious language of whales. They bathed in special pools, prayed, spoke quietly, and avoided startling movements that might offend whales. Right before the hunt, the whalers sang a song asking the whale to give itself.

In Makah and Nuu-chah-nulth belief, as in many Arctic cultures, whales weren’t just taken—they willingly gave themselves to human communities. A whale that offered its body wasn’t sentencing itself to death. It was choosing to be killed by hunters who had demonstrated, through good behavior and careful adherence to rituals, that they would treat its remains in a way that would allow it to be reborn. Yupik tradition, for example, holds that beluga whales once lived on land and long to return to terra firma. In exchange for offering itself to a Yupik community, a beluga expected to have its bones given the ritualistic treatment that would allow it to complete this transition and return to land, perhaps as one of the wolves that would gnaw on the whale’s bones.

According to Hill, many of the objects aiding this reciprocity—vessels used to offer whales a drink of fresh water, amulets that hunters used to negotiate relationships with animal spirits—weren’t just reserved for shamanistic ceremonies. They were part of everyday life; the physical manifestation of an ongoing, daily dialogue between the human and animal worlds.


While Westerners domesticated and eventually industrialized the animals we eat—and thus came to view them as dumb and inferior—Arctic cultures saw whale hunting as a match between equals. Bipedal humans with rudimentary technology faced off against animals as much as 1,000 times their size that were emotional, thoughtful, and influenced by the same social expectations that governed human communities. In fact, whales were thought to live in an underwater society paralleling that above the sea.

a bowhead whale swimming amid multi-layer sea ice

It’s difficult to assess populations of animals that swim under the ice, far from view, like bowhead whales. But experienced Iñupiat whalers are good at it. Photo by Steven Kazlowski/Minden Pictures

Throughout history, similar beliefs have guided other human-animal relationships, especially in hunter-gatherer cultures that shared their environment with big, potentially dangerous animals. Carvings left behind by the Tunit, for example, suggest a belief that polar bears possessed a kind of personhood allowing them to communicate with humans; while some Inuit believed walruses could listen to humans talking about them and react accordingly.

Whether or not those beliefs are demonstrably true, says Hill, they “make room for animal intelligence and feelings and agency in ways that our traditional scientific thinking has not.”

Today, as archaeologists like Hill and Matthew Betts shift their interpretation of the past to better reflect Indigenous worldviews, biologists too are shedding new light on whale behavior and biology that seems to confirm the traits Indigenous people have attributed to whales for more than 1,000 years. Among them is Hal Whitehead, a professor at Dalhousie University in Nova Scotia who argues that cetaceans have their own culture—a word typically reserved for human societies.

By this definition, culture is social learning that’s passed down from one generation to the next. Whitehead finds evidence for his theory in numerous recent studies, including one that shows bowhead whales in the North Pacific, off the Alaskan coast, and in the Atlantic Ocean near Greenland sing different songs, the way human groups might have different styles of music or linguistic dialects. Similarly, pods of resident killer whales living in the waters off south Vancouver Island greet each other with different behaviors than killer whales living off north Vancouver Island, despite the fact that the groups are genetically almost identical and have overlapping territories.

Plus, calves spend years with their mothers, developing the strong mother-offspring bonds that serve to transfer cultural information, and bowhead whales live long enough to accumulate the kind of environmental knowledge that would be beneficial to pass on to younger generations. We know this largely because of a harpoon tip that was found embedded in a bowhead in northern Alaska in 2007. This particular harpoon was only manufactured between 1879 and 1885 and wasn’t used for long after, meaning that the whale had sustained its injury at least 117 years before it finally died.

Other beliefs, too, are proving less farfetched than they once sounded. For years, scientists believed whales couldn’t smell, despite the fact that Iñupiat hunters claimed the smell of woodsmoke would drive a whale away from their camp. Eventually, a Dutch scientist dissecting whale skulls proved the animals did, indeed, have the capacity to smell. Even the Yupik belief that beluga whales were once land-dwelling creatures is rooted in reality: some 50 million years ago, the ancestor of modern-day whales walked on land. As if recalling this, whale fetuses briefly develop legs before losing them again.

An Inuit hunter sits on a whale that’s been hauled to shore for butchering in Point Hope, Alaska, in 1900. Photo by Hulton Deutsch/Getty ImagesInuit hunters in Utqiaġvik, Alaska, paddle an umiak after a bowhead whale. Photo by Galen Rowell/Getty Images

None of this suggests that whales freely give themselves to humans. But once you understand the biological and intellectual capabilities of whales—as whaling cultures surely did—it’s less of a leap to conclude that cetaceans live in their own underwater society, and can communicate their needs and wishes to humans willing to listen.


With the dawn of the 20th century and the encroachment of Euro-Americans into the North, Indigenous whaling changed drastically. Whaling in the Makah and Nuu-chah-nulth Nations essentially ended in the 1920s after commercial whalers hunted the gray whale to near extinction. In Chukotka, Russian authorities in the 1950s replaced community-based whaling with state-run whaling.

Even the whaling strongholds of Alaska’s Iñupiat villages weren’t immune. In the 1970s, the International Whaling Commission ordered a halt to subsistence bowhead whaling because US government scientists feared there were just 1,300 of the animals left. Harry Brower Sr. and other whaling captains who’d amassed lifetimes of knowledge knew that figure was wrong.

But unlike other whaling cultures, Iñupiat whalers had the means to fight back, thanks to taxes they had collected from a nearby oil boom. With the money, communities hired Western-trained scientists to corroborate traditional knowledge. The scientists developed a new methodology that used hydrophones to count bowhead whales beneath the ice, rather than extrapolating the population based on a count of the visible bowheads passing by a single, ice-free locale. Their findings proved bowheads were far more numerous than the government had previously thought, and subsistence whaling was allowed to continue.

Elsewhere, too, whaling traditions have slowly come back to life. In 1999, the Makah harvested their first whale in over 70 years. The Chukchi were allowed to hunt again in the 1990s.

Yet few modern men knew whales as intimately as Brower. Although he eschewed some traditions—he said he never wanted his own whaling song to call a harpooned whale to the umiak, for exampleBrower had other ways of communicating with whales. He believed that whales listened, and that if a whaler was selfish or disrespectful, whales would avoid him. He believed that the natural world was alive with animals’ spirits, and that the inexplicable connection he’d felt with whales could only be explained by the presence of such spirits.

And he believed that in 1986, a baby whale visited him in an Anchorage hospital to show him how future generations could maintain the centuries-long relationship between humans and whales. Before he died, he told his biographer Karen Brewster that although he believed in a Christian heaven, he personally thought he would go elsewhere. “I’m going to go join the whales,” he said. “That’s the best place, I think. … You could feed all the people for the last time.”

Perhaps Brower did become a whale and feed his people one last time. Or perhaps, through his deep understanding of whale biology and behavior, he passed down the knowledge that enabled his people to feed themselves for generations to come. Today, the spring whaling deadline he proposed based on his conversation with the baby whale is still largely observed, and bowhead whales continue to sustain Iñupiat communities, both physically and culturally.

Correction: This article has been updated to clarify the original purpose of the whaling amulet that caught Erica Hill’s attention in the Smithsonian warehouse.


Author bio Krista Lee Langlois is an independent journalist, essayist, and “aquaphile.” She lived in the Marshall Islands in 2006 and now writes about the intersection of people and nature from a landlocked cabin outside Durango, Colorado.

Anúncios

Os motivos por trás da Guerra dos Chimpanzés, a única registrada entre animais (BBC Brasil)

9 abril 2018Três chimpanzés do Parque Nacional de Gombe nos anos 1970

GEZA TELEKI. A eleição de um macaco do norte do Parque Nacional de Gombe como macho alfa causou tensão na comunidade de chimpanzés e, principalmente, com dois rivais, Charlie e Hugh

A única guerra civil documentada entre chimpanzés selvagens começou com um assassinato brutal.

Era janeiro de 1974, e um chimpanzé chamado Godi fazia sua refeição, sozinho, nos galhos de uma árvore no Parque Nacional de Gombe, na Tanzânia.

Mas Godi não reparou que, enquanto comia, oito macacos o rodearam. “Ele pulou da árvore e correu, mas eles o agarraram”, disse o primatologista britânico Richard Wrangham ao documentário da BBC The Demonic Ape (O Macaco Demoníaco, em tradução livre).”Um deles conseguiu agarrar um de seus pés, outro lhe prendeu pela mão. Ele foi imobilizado e surrado. O ataque durou mais de cinco minutos e, quando o deixaram, ele mal conseguia se mover.

“Godi nunca mais foi visto.

O episódio é conhecido como o início do que a famosa primatologista britânica Jane Goodall chamou de “A Guerra dos 4 Anos”, o conflito que dividiu uma comunidade de chimpanzés em Gombe e desatou uma onda de assassinatos e violência que, desde então, nunca mais foi registrada.

Mão de um chimpanzé

GETTY IMAGES. O assassinato brutal do primata Godi marcou o início da sangrenta “Guerra de 4 anos” dos chimpanzés em Gombe

No entanto, o motivo exato e a causa da divisão são um “eterno mistério”, disse Joseph Feldblum, professor de antropologia evolutiva da Universidade de Duke, nos Estados Unidos, em um comunicado da instituição.

No mês passado, Feldblum liderou um estudo publicado na revista científica American Journal of Physical Anthropology que revela a história de “poder, ambição e ciúmes” que deu origem à guerra entre os primatas.

 

Macacos e humanos

Feldblum está há 25 anos arquivando e digitalizando as anotações que Goodall fez durante seus mais de 55 anos vivendo no Parque Nacional de Gombe.

A primatologista, que na última terça-feira completou 84 anos, mudou tudo o que acreditávamos saber sobre os chimpanzés (e sobre os seres humanos) ao descobrir que esses macacos fabricavam e usavam ferramentas, tinham uma linguagem primitiva e eram capazes de entender o que seus pares pensavam.

Mas Goodall também descobriu a crueldade que esses animais podiam demonstrar.

Jane Goodall com seu famoso boneco em 2018

GETTY IMAGES. A primatologista Jane Goodall, que lidera uma fundação de pesquisa e conservação com seu nome, acompanhou toda a guerra dos chimpanzés nos anos 1970

Foram quatro anos documentando saques, surras e assassinatos entre as facções Kasakela e Kahama, que ficavam ao norte e ao sul do parque, respectivamente.

Nesse tempo, por exemplo, um terço das mortes de chimpanzés machos em Gombe foram perpetreadas pelos próprios animais.

A guerra, disse Goodall no documentário da BBC, “só fez com que os chimpanzés se parecessem ainda mais conosco do que se pensava”.

A violência foi tão excessiva e única que alguns investigadores sugeriram que ela foi provocada involuntariamente pela própria Goodall, que montou uma estação de observação no local onde os animais recebiam alimentos.

De acordo com essas teorias, “as duas comunidades de chimpanzés poderiam ter existido o tempo todo ou estavam se dissolvendo quando Goodall começou sua pesquisa, e a estação de alimentação os reuniu em uma trégua temporária até que eles se separaram novamente”, disse o comunicado da Universidade de Duke.

“Mas os novos resultados de uma equipe de Duke e da Universidade Estadual do Arizona sugerem que alguma coisa a mais estava acontecendo.”

Chimpanzés brigando

GETTY IMAGES. Os chimpanzés são capazes de violência, mas pesquisadores dizem que o ocorrido entre 1974 e 1978 excedeu todos os registros de brutalidade

 

Amigos e inimigos

No novo estudo, os pesquisadores analisaram as mudanças nas alianças entre 19 chimpanzés machos durante os sete anos anteriores à guerra.

Para isso, elaboraram mapas detalhados das redes sociais dos primatas, nas quais os machos eram considerados amigos se fossem vistos chegando juntos à estação de alimentação com maior frequência.

“Sua análise sugere que, durante os primeiros anos, entre 1967 e 1970, os machos do grupo original estavam misturados”, disse Duke.

Foi aí que a comunidade começou a se dividir: enquanto alguns passavam mais tempo no norte, outros estavam a maior parte do tempo no sul.

Em 1972, a socialização entre os machos já ocorria exclusivamente dentro das facções Kasakela ou Kahama.

Silhueta de um chimpanzé

GETTY IMAGES. Ao ver chegar os macacos do sul, os do norte “subiam nas árvores, havia muitos gritos e demonstrações de poder”, diz um novo estudo sobre o episódio

Ao se encontrarem, eles começavam a atirar galhos uns nos outros, a gritar ou fazer outras demonstrações de força.

“Escutávamos gritos do sul e dizíamos: ‘Os machos do sul estão vindo!'”, relembra Anne Pusey, professora de antropologia evolutiva da Universidade de Duke que esteve em Gombe com Goodall e é coautora do estudo atual.

“Nessa hora, todos os machos do norte subiam nas árvores e ouvíamos muitos gritos e demonstrações de poder.”

Três suspeitos

A partir do momento que ocorreu a divisão entre os grupos, os pesquisadores acreditam que o conflito surgiu por causa de “uma luta pelo poder entre três machos de alta categoria”: Humphrey, um macho alfa recém-coroado pelo grupo do norte, e seus rivais do sul, Charlie e Hugh.

Chimpanzé sofrendo

GETTY IMAGES. Violência entre três machos líderes afetou toda a rede de vínculos sociais, sem distinguir idade nem sexo

“Humphrey era grande e se sabia que ele atirava pedras, o que era assustador. Ele conseguia intimidar Charlie e Hugh separadamente, mas, quando estavam juntos, ele se mantinha fora do caminho”, diz Pussey no comunicado da universidade.

Durante quatro anos, o grupo de Humphrey destruiu o grupo do sul, e diversos machos “rebeldes” morreram ou desapareceram. O maior dos grupos invadia sistemativamente o território alheio e, se encontrasse um chimpanzé rival, o atacava cruelmente e o deixava morrer em decorrência dos ferimentos.

De acordo com a pesquisa, a disponibilidade de fêmeas foi mais baixa do que o normal nesse período, o que provavelmente exacerbou a luta pelo domínio do território.

A violência, por sua vez, não se limitou a esses três machos rivais, mas afetou toda a rede de vínculos sociais dos primatas, sem distinguir idade nem sexo.

Os pesquisadores reconhecem que a falta de outros eventos semelhantes na natureza torna mais difícil comparar os novos resultados, mas o trabalho pode trazer certa paz a Goodall.

“A situação foi terrível”, disse a britânica, reconhecendo que sua estação de observação de fato pode ter “aumentado a violência” entre os primatas.

“Acho que a parte mais triste foi ter observado a sequência de eventos em que uma comunidade maior aniquilou por completo a menor e tomou seu território.”

So killer whales can talk. Welcome to a brave new world of cross-species chat (The Guardian)

Opinion

Wikie the orca is more mimic than raconteur, but the potential is awesome. Imagine dolphins tackling politicians on pollution

A killer whale.

Abridge in cultures has occurred. A cognitive chasm between intelligent creatures has been crossed. Of all the spectacular times for you to be alive, you happen to have been born in an age when killer whales started talking to the damn dirty apes who were willing to listen. Though this sounds like some sort of sci-fi dream/nightmare, I am here to assure you that this is real. Remain calm, but stay vigilant around all marine mammals at this time. We may be in for a rocky time, as you shall discover.

Let us begin by examining the facts. First, it’s true. As you may have heard by now, a captive killer whale called Wikie, housed at Marineland in Antibes, France, is uttering noises that mimic the human sounds “Hello” and “Bye-bye” as well as “One, two, three” plus, apparently, the haunting word “Amy” – the name of its trainer. Predictably, within hours of the release of the scientific paper, Wikie has become something of an online celebrity.

This week, after the news broke about Wikie’s great feat, a number of vocal animal welfare charities were calling for her release from captivity. This troubled me a little. Really? I thought. Is that really a good idea?

Killer whales (like all dolphins) are adept at horizontal learning, after all. They copy one another. They have sounds for objects, possibly names. They have dialects. They transmit behaviours. In other words, they have culture like we do. Might the once captive Wikie somehow spoil their untamed wildness with her newly learned human vernacular? What if this captive dolphin, somehow released into the wild with a human greeting (“Hello!”) should corrupt the wild dolphins it comes across? What then? I dread to think, but the idea is entertaining to consider so let us do just that.

Let us imagine pods of wild dolphins screaming “Goodbye” at boatloads of tourists that encroach on their hunting grounds each year. Imagine them saying “Bye-bye” to trawlers. Imagine them ruining countless nature documentaries by screaming “Hello” to BBC camera crews while filming.

And what if Wikie and her kind later develop sarcasm? Can you imagine, in an age where our oceans become bereft and depleted of nutrition, the words “So long and thanks for all the fish!”, delivered in a sarcastic tone? In a perverse sort of way, I suspect Douglas Adams would have laughed long and loud at this idea. And then wept.

Listen to killer whales mimicking human voices – audio

But there are positives to this possible cross-species dialogue, and perhaps it is this potential that we should focus on. Imagine a non-human animal that could speak up – in human words – against the degradation of a vast ecosystem like that of the oceans? In such a world, perhaps modern politics would find itself a new enemy in marine mammals like Wikie. One can imagine, for instance, in some alternative universe, a language-endowed Wikie being invited to speak at Davos or some other God-awful international event.

One can imagine the soundbites (“Amy?”); the 7.45am BBC Breakfast interview; the cosy press conferences with Wikie, wide-eyed in a giant blow-up birthing pool in front of the cameras, next to a shady foreign president secretly plotting her kind’s political downfall while sipping imported water from a non-recyclable plastic bottle. (While writing this it strikes me how, in moments like these, just how so many of us would side with these talkative killer whales). But alas, such imaginative scenarios are just that – imaginative.

You knew this bit was coming. It is time to burst the bubble about this female killer whale. Wikie has a kind of magic about her, but it is not yet a two-way conversation. She is a mimic, pure and simple and she is hungry for her fish rewards. In the same way as a 14-year-old can armpit-fart his way through Bach’s Fifth Symphony to achieve 1,000-plus views on YouTube, without ever truly knowing Bach, this killer whale has hit upon a neat trick for reward by exhaling in a measured way that sounds a little like human voice.

But that doesn’t make the science hogwash. Far from it. It’s a beginning. And all scientific journeys have a beginning. We’ll need wild, untainted, unspoiled populations to test ideas on. We need to get away from fish rewards. We need to move away from captive research. This is a start. It’s not the end. They may one day talk with us, but not like this.

And so, in my wildest dreams it won’t be a “bye-bye” or a “hello” that curries favour with an intelligent species such as the killer whale, but a word of more depth: a word like “friend” or “partner” or “respect”. And further down the line maybe we could manage something else. Dialogue. Truth. Meaning.

As of recent times, these are no longer uniquely human concepts when it comes to zoology. Welcome to the brave new world. You happen to be alive in it. But who else is listening? Increasingly, we shall get to decide. Bye-bye, or hello: you and I get to choose.

Jules Howard is a zoologist and the author of Sex on Earth, and Death on Earth

Orcas can imitate human speech, research reveals (The Guardian)

Killer whales able to copy words such as ‘hello’ and ‘bye bye’ as well as sounds from other orcas, study shows

High-pitched, eerie and yet distinct, the sound of a voice calling the name “Amy” is unmistakable. But this isn’t a human cry – it’s the voice of a killer whale called Wikie.

New research reveals that orcas are able to imitate human speech, in some cases at the first attempt, saying words such as “hello”, “one, two” and “bye bye”.

The study also shows that the creatures are able to copy unfamiliar sounds produced by other orcas – including a sound similar to blowing a raspberry.

Scientists say the discovery helps to shed light on how different pods of wild killer whales have ended up with distinct dialects, adding weight to the idea that they are the result of imitation between orcas. The creatures are already known for their ability to copy the movements of other orcas, with some reports suggesting they can also mimic the sounds of bottlenose dolphins and sea lions.

“We wanted to see how flexible a killer whale can be in copying sounds,” said Josep Call, professor in evolutionary origins of mind at the University of St Andrews and a co-author of the study. “We thought what would be really convincing is to present them with something that is not in their repertoire – and in this case ‘hello’ [is] not what a killer whale would say.”

Wikie is not the first animal to have managed the feat of producing human sounds: dolphins, elephants, parrots, orangutans and even beluga whales have all been captured mimicking our utterances, although they use a range of physical mechanisms to us to do so. Noc, the beluga whale, made novel use of his nasal cavities, while Koshik, an Indian elephant jammed his trunk in his mouth, resulting in the pronouncement of Korean words ranging from “hello” to “sit down” and “no”.

But researchers say only a fraction of the animal kingdom can mimic human speech, with brain pathways and vocal apparatus both thought to determine whether it is possible.

“That is what makes it even more impressive – even though the morphology [of orcas] is so different, they can still produce a sound that comes close to what another species, in this case us, can produce,” said Call.

He poured cold water, however, on the idea that orcas might understand the words they mimic. “We have no evidence that they understand what their ‘hello’ stands for,” he said.

Writing in the journal Proceedings of the Royal Society B: Biological Sciences, researchers from institutions in Germany, UK, Spain and Chile, describe how they carried out the latest research with Wikie, a 14-year-old female orca living in an aquarium in France. She had previously been trained to copy actions performed by another orca when given a human gesture.

After first brushing up Wikie’s grasp of the “copy” command, she was trained to parrot three familiar orca sounds made by her three-year old calf Moana.

Wikie was then additionally exposed to five orca sounds she had never heard before, including noises resembling a creaking door and the blowing a raspberry.

Finally, Wikie was exposed to a human making three of the orca sounds, as well as six human sounds, including “hello”, “Amy”, “ah ha”, “one, two” and “bye bye”.

“You cannot pick a word that is very complicated because then I think you are asking too much – we wanted things that were short but were also distinctive,” said Call.

Throughout the study, Wikie’s success was first judged by her two trainers and then confirmed from recordings by six independent adjudicators who compared them to the original sound, without knowing which was which.

The team found that Wikie was often quickly able to copy the sounds, whether from an orca or a human, with all of the novel noises mimicked within 17 trials. What’s more, two human utterances and all of the human-produced orca sounds were managed on the first attempt – although only one human sound – “hello” – was correctly produced more than 50% of the time on subsequent trials.

The matching was further backed up through an analysis of various acoustic features from the recordings of Wikie’s sounds.

While the sounds were all made and copied when the animals’ heads were out of the water, Call said the study shed light on orca behaviour.

“I think here we have the first evidence that killer whales may be learning sounds by vocal imitation, and this is something that could be the basis of the dialects we observe in the wild – it is plausible,” said Call, noting that to further test the idea, trials would have to be carried out with wild orcas.

Diana Reiss, an expert in dolphin communication and professor of psychology at Hunter College, City University of New York, welcomed the research, noting that it extends our understanding of orcas’ vocal abilities, with Wikie able to apply a “copy” command learned for imitation of actions to imitation of sounds.

Dr Irene Pepperberg, an expert in parrot cognition at Harvard University, also described the study as exciting, but said: “A stronger test would have been whether the various sounds produced could be correctly classified by humans without the models present for comparison.”

Language is learned in brain circuits that predate humans (Georgetown University)

PUBLIC RELEASE: 

GEORGETOWN UNIVERSITY MEDICAL CENTER

WASHINGTON — It has often been claimed that humans learn language using brain components that are specifically dedicated to this purpose. Now, new evidence strongly suggests that language is in fact learned in brain systems that are also used for many other purposes and even pre-existed humans, say researchers in PNAS (Early Edition online Jan. 29).

The research combines results from multiple studies involving a total of 665 participants. It shows that children learn their native language and adults learn foreign languages in evolutionarily ancient brain circuits that also are used for tasks as diverse as remembering a shopping list and learning to drive.

“Our conclusion that language is learned in such ancient general-purpose systems contrasts with the long-standing theory that language depends on innately-specified language modules found only in humans,” says the study’s senior investigator, Michael T. Ullman, PhD, professor of neuroscience at Georgetown University School of Medicine.

“These brain systems are also found in animals – for example, rats use them when they learn to navigate a maze,” says co-author Phillip Hamrick, PhD, of Kent State University. “Whatever changes these systems might have undergone to support language, the fact that they play an important role in this critical human ability is quite remarkable.”

The study has important implications not only for understanding the biology and evolution of language and how it is learned, but also for how language learning can be improved, both for people learning a foreign language and for those with language disorders such as autism, dyslexia, or aphasia (language problems caused by brain damage such as stroke).

The research statistically synthesized findings from 16 studies that examined language learning in two well-studied brain systems: declarative and procedural memory.

The results showed that how good we are at remembering the words of a language correlates with how good we are at learning in declarative memory, which we use to memorize shopping lists or to remember the bus driver’s face or what we ate for dinner last night.

Grammar abilities, which allow us to combine words into sentences according to the rules of a language, showed a different pattern. The grammar abilities of children acquiring their native language correlated most strongly with learning in procedural memory, which we use to learn tasks such as driving, riding a bicycle, or playing a musical instrument. In adults learning a foreign language, however, grammar correlated with declarative memory at earlier stages of language learning, but with procedural memory at later stages.

The correlations were large, and were found consistently across languages (e.g., English, French, Finnish, and Japanese) and tasks (e.g., reading, listening, and speaking tasks), suggesting that the links between language and the brain systems are robust and reliable.

The findings have broad research, educational, and clinical implications, says co-author Jarrad Lum, PhD, of Deakin University in Australia.

“Researchers still know very little about the genetic and biological bases of language learning, and the new findings may lead to advances in these areas,” says Ullman. “We know much more about the genetics and biology of the brain systems than about these same aspects of language learning. Since our results suggest that language learning depends on the brain systems, the genetics, biology, and learning mechanisms of these systems may very well also hold for language.”

For example, though researchers know little about which genes underlie language, numerous genes playing particular roles in the two brain systems have been identified. The findings from this new study suggest that these genes may also play similar roles in language. Along the same lines, the evolution of these brain systems, and how they came to underlie language, should shed light on the evolution of language.

Additionally, the findings may lead to approaches that could improve foreign language learning and language problems in disorders, Ullman says.

For example, various pharmacological agents (e.g., the drug memantine) and behavioral strategies (e.g., spacing out the presentation of information) have been shown to enhance learning or retention of information in the brain systems, he says. These approaches may thus also be used to facilitate language learning, including in disorders such as aphasia, dyslexia, and autism.

“We hope and believe that this study will lead to exciting advances in our understanding of language, and in how both second language learning and language problems can be improved,” Ullman concludes.

Cultura primata (Revista Fapesp)

Transmissão de práticas de uso de ferramentas por macacos-prego ajuda a repensar o papel das tradições na evolução

MARIA GUIMARÃES | ED. 259 | SETEMBRO 2017

Podcast: Eduardo Ottoni

Com uma pedra erguida acima da cabeça, o jovem Porthos bate vigorosamente no chão arenoso de modo a abrir um buraco. Seu objetivo: uma aranha, que logo consegue desentocar e rola entre as mãos para tontear a presa que em seguida come. Ele é um macaco-prego da espécie Sapajus libidinosus, habitante do Parque Nacional Serra da Capivara, no Piauí, e objeto de estudo de pesquisadores do Instituto de Psicologia da Universidade de São Paulo (IP-USP). O biólogo Tiago Falótico tem caracterizado o uso de ferramentas por esses animais (ver Pesquisa FAPESP nº 196) e mostrou, em artigo publicado em julho na revista Scientific Reports, que a ação do jovem macho envolve conhecimento, aprendizado e transmissão de práticas culturais – ou tradições, como alguns preferem chamar quando os sujeitos não são humanos – dentro de grupos sociais. A pesquisa está no bojo de um corpo teórico que busca entrelaçar biologia, ciências sociais e humanas e recém-desembocou na formação da Sociedade de Evolução Cultural. Sua reunião inaugural acaba de acontecer na Alemanha, entre 13 e 15 de setembro.

Até agora, o uso de pedras como ferramentas para cavar só foi documentado nessa população. Especialmente quando se trata de desentocar aranhas, é preciso experiência. O estudo, resultado de observações feitas durante o doutorado de Falótico, encerrado em 2011 sob orientação do biólogo Eduardo Ottoni, mostra que quase 60% dos adultos e jovens (como Porthos) têm sucesso na tarefa. Macacos juvenis (o correspondente a crianças), por outro lado, só conseguem em pouco mais de 30% dos casos. Isso acontece porque é preciso reconhecer o revestimento de seda que fecha a toca do aracnídeo, sinal de que o habitante está lá dentro. “Os juvenis às vezes cavam uma toca que acabou de ser aberta por outro macaco”, conta Falótico. Estruturas subterrâneas, parecidas com batatas, da planta conhecida como farinha-seca (Thiloa glaucocarpa), também são desenterradas com mais eficiência pelos adultos. Já as raízes de louro (Ocotea), outro alimento desses primatas, apesar de envolverem o uso de pedras maiores, não parecem apresentar um desafio especial para os aprendizes. Macacos dos dois sexos se mostraram igualmente capazes de cavar com pedras, com uma taxa de sucesso equivalente, embora eles pareçam ter mais interesse pela atividade: entre as 1.702 situações observadas, 77% envolviam machos e apenas 23%, fêmeas.

“Esperávamos encontrar uma correlação entre o uso de ferramentas e a escassez de alimentos, mas não foi o que vimos”, conta Falótico. Se os macacos da serra da Capivara encontram algo comestível que exija o uso de ferramentas, recorrem a elas. Seu modo de vida, em que passam metade do tempo no chão rodeados de pedras e gravetos, parece ser propício ao desenvolvimento das habilidades. Mas não é só isso. Embora não haja diferença entre os sexos nos hábitos alimentares, as fêmeas nunca usam gravetos – que seus companheiros masculinos utilizam para desentocar lagartos de frestas e retirar insetos de troncos, por exemplo. Há diferença apenas, aparentemente, no interesse. “Quando um macho vê outro usar uma vareta, ele observa atento; já uma fêmea, mesmo que esteja ao lado daquele usando a ferramenta, não se interessa e olha para o outro lado!”

Os macacos da mesma espécie que habitam a fazenda Boa Vista, em Gilbués, cerca de 300 quilômetros (km) para sudoeste, têm tradições distintas no uso de ferramentas. Ali, uma área com mais influência de Cerrado do que Caatinga, as pedras são menos abundantes, mas necessárias (e usadas) para quebrar cocos. Gravetos estão por toda parte, mas não têm uso. Essa diferença cultural entre grupos de macacos foi explorada em um experimento feito pelo psicólogo Raphael Moura Cardoso durante o doutorado, orientado por Eduardo Ottoni, e relatado em artigo de 2016 na Biology Letters. Eles puseram – tanto na fazenda Boa Vista como na serra da Capivara – caixas de acrílico recheadas de melado de cana. O único jeito de retirar a guloseima era por meio de uma fenda no alto com largura suficiente apenas para varetas. “Na serra da Capivara, um macho logo acertou uma pedrada na caixa”, lembra Ottoni, que, previdente, tinha planejado o aparato “à prova de macaco-prego”. “Quando nada aconteceu, ele largou a pedra, coçou a cabeça e pegou um graveto.” Ele brinca que nem precisou editar o vídeo para mostrar em um congresso – foi uma ação contínua e imediata. Ao longo de cinco dias de exposição à caixa, 10 dos 14 machos usaram o graveto logo na primeira sessão, e apenas os três mais jovens não foram bem-sucedidos. Os demais conseguiram um sucesso de 90% na empreitada. As fêmeas não tentaram, assim como os macacos da fazenda Boa Vista. Lá, os pesquisadores até tentaram ajudar: depois de seis horas expostos à tarefa, os macacos deparavam com um graveto já fincado na fenda. Mesmo tirando e lambendo o melado da ponta, nenhum deles voltou a inserir a ferramenta na caixa ao longo de 13 dias de experimento. Uma surpresa foi que os macacos da Boa Vista, exímios quebradores de coco, não tentaram partir a caixa. “Eu esperava isso deles, não dos outros”, diz Ottoni.

Aprendizado social

Os resultados, surpreendentes, podem reforçar a importância da transmissão de tradições entre os macacos. A capa da edição de 25 de julho deste ano da revista PNAS traz justamente a foto de um macaco-prego da fazenda Boa Vista comendo uma castanha que conseguiu quebrar com a ajuda de uma grande pedra redonda, observado de perto por um jovem. A imagem anuncia a coletânea especial sobre como a cultura se conecta à biologia, da qual faz parte um artigo do grupo liderado pelas primatólogas Patrícia Izar, do IP-USP, Dorothy Fragaszy, da Universidade da Georgia, nos Estados Unidos, e Elisabetta Visalberghi, do Instituto de Ciências e Tecnologias Cognitivas, na Itália, sobre os macacos da fazenda Boa Vista, que estudam sistematicamente desde 2006. Nas observações recolhidas ao longo desse tempo, chama a atenção a tolerância dos adultos em relação aos jovens aprendizes que olham de perto e até comem pedaços dos cocos partidos. “Os adultos competem pelos recursos e os imaturos podem ficar perto”, conta Patrícia. As análises publicadas no artigo recente mostram muito mais do que proximidade: os quebradores de coco influenciam a atividade dos outros, sobretudo os jovens, que também começam a manipular pedras e cocos. Isso dura alguns minutos. “A tradição canaliza a atividade para o mesmo tipo de ação importante para essa tradição”, define.

Patrícia ressalta que os macacos nascem nesse contexto. “Muitas vezes vemos filhotes nas costas das mães enquanto elas quebram”, conta. Com esse aprendizado contínuo, acabam se tornando especialistas na tarefa. Mas não basta observar, e daí a importância de os filhotes serem atraídos pela ação dos adultos – principalmente os mais eficazes. “O sucesso passa pela percepção da tarefa e das propriedades da ferramenta”, detalha, descrevendo um complexo corpo-ferramenta em que é constantemente necessário ajustar força, gestos e postura. Quando quebram tucum, um coquinho menos resistente, os macacos ajustam a força das pancadas depois de ouvirem o som da superfície rachando, o grupo mostrou em artigo do ano passado na Animal Behaviour. Para cocos mais difíceis, eles escolhem pedras que podem chegar a ser mais pesadas do que o próprio corpo. E a seleção da pedra é criteriosa, conforme mostrou um experimento em que Patrícia e seu grupo forneceram pedras artificiais com diferentes tamanhos, pesos e densidades. As pedras grandes logo atraíam a atenção dos macacos, mas se fossem pouco densas – mais leves do que aparentavam – eram abandonadas. “Eles têm a percepção de que o peso é importante na quebra”, diz Patrícia.

Tolerância: macho adulto da fazenda Boa Vista come castanha partida observado de perto por jovem

Essas sociedades primatas alteram o ambiente. Macacos escolhem pedras ou troncos achatados como base para quebrar coco, e para lá carregam as raras pedras grandes e duras que encontram no ambiente. Essa conformação é importante não só por criar oficinas de quebra, mas por canalizar a possibilidade de aprendizado, já que todos sabem onde a atividade acontece e pode ser observada. “Não faz sentido pensar em maturação motora independente do contexto social, alimentar”, afirma a bióloga Briseida Resende, também do IP-USP e coautora do artigo da PNAS. O desenvolvimento individual depende das experiências de cada um, de suas capacidades físicas e do acervo acumulado pelo grupo, no qual uma inovação criada pode se disseminar, perpetuar-se e fazer parte da cultura mantida por gerações. Resende defende que indivíduo e sociedade são indissociáveis, embora historicamente tenham sido vistos como entidades distintas.

Teoria revista

Reunir a evolução cultural e a biológica é justamente o foco da síntese estendida, agora sedimentada com a fundação, em 2016, da Sociedade de Evolução Cultural – o primeiro presidente é o zoólogo Peter Richerson, da Universidade da Califórnia em Davis, cujo grupo privilegia a estatística. Essa visão conjunta amplia o olhar evolutivo, já que a transmissão de ideias ou inovações não se dá apenas de pais para filhos e pode trazer vantagens seletivas favorecendo as capacidades cognitivas e sociais relevantes. Considera também que a cultura pode influenciar aspectos físicos, como a conformação e o tamanho do cérebro, ou o desenvolvimento de habilidades que por sua vez sedimentam o comportamento. Os genes e a cultura, duas vias de transmissão de informação, relacionam-se, portanto, por uma via de mão dupla.

Jovens aprendizes tentam tirar proveito de escavação feita por fêmea

A oportunidade de ver comportamentos surgirem e se espalhar é rara, e por isso abordagens experimentais que provocam inovações são um acréscimo importante aos comportamentos diversos dos macacos-prego do Piauí. Ferramentas estatísticas recentes podem ajudar a aprofundar essa compreensão, como a Análise de Difusão Baseada em Redes (Network-Based Diffusion Analysis) que o grupo de Ottoni começa a usar. “O programa monta uma rede social aleatória e compara à real”, explica o pesquisador, que torna as análises mais robustas inserindo características medidas nos sujeitos em causa. Em agosto de 2016 ele apresentou, no congresso da Sociedade Primatológica Internacional, em Chicago, resultados do experimento feito pela bióloga Camila Coelho durante doutorado orientado por ele com um período passado na Universidade de Durham, no Reino Unido, para aprender o método. Os resultados indicam que, no caso dos macacos-prego, o aprendizado social prevê a difusão de informação na espécie.

Até meio século atrás, o uso de ferramentas era considerado privilégio humano. Ao observar chimpanzés na Tanzânia, a inglesa Jane Goodall derrubou essa exclusividade e, de certa maneira, causou a redefinição das fronteiras entre gente e bicho. Muito se descobriu de lá para cá, mas falar em cultura animal ainda esbarra em certo desconforto. Talvez não por muito mais tempo.

O uso de pedras para escavar só foi descrito na serra da Capivara

Sob o comando de hormônios

O cuidado com os filhotes está ligado ao hormônio oxitocina em mamíferos. O grupo liderado por Maria Cátira Bortolini, da Universidade Federal do Rio Grande do Sul, descreveu há poucos anos as variações na molécula de oxitocina em espécies de macacos nas quais há bons pais (ver Pesquisa FAPESP 228). Ensaios farmacológicos feitos no laboratório do bioquímico Claudio Costa-Neto, da Faculdade de Medicina de Ribeirão Preto da USP, agora desvendaram o caminho da oxitocina dentro das células e verificaram que os receptores das formas alteradas ficam mais expostos nas membranas das células, de maneira que o sistema não se dessensibiliza. “É como se o macaco recebesse constantemente a instrução ‘tenho que cuidar dos filhotes’”, explica Cátira. Faz diferença para a sobrevivência de saguis, que frequentemente têm filhotes gêmeos, por exemplo.

O resultado está em artigo publicado em agosto na PNAS, que também descreve o resultado da aplicação dessas oxitocinas em ratos por meio de borrifadas nasais, experimento realizado em colaboração com o fisiologista Aldo Lucion, da UFRGS. As fêmeas lactantes, já inundadas de oxitocina, alteraram pouco o comportamento. Mas os machos tratados com o hormônio alteraram radicalmente o hábito de ignorar os filhotes e correram para cheirá-los, uma reação que foi três vezes mais rápida com a oxitocina de sagui.

Os cebídeos, família que inclui os macacos-prego, também têm um tipo de oxitocina que aumenta a propensão à paternidade ativa. Os grupos de Cátira e de Ottoni recentemente iniciaram uma colaboração para investigar as características genéticas em machos mais e menos cuidadores. “Já conseguimos extrair material genético de amostras de fezes e estamos selecionando genes candidatos a serem rastreados”, conta ela, fascinada com a tolerância dos machos e as habilidades cognitivas dos primatas do Piauí. “A capacidade de inovar, por um lado, e a de sentar e observar, por outro, são necessárias para o desenvolvimento e a transmissão de traços culturais adaptativos e certamente há um cenário genético por trás disso.”

Projetos
1. Uso de ferramentas por macacos-prego (Sapajus libidinosus) selvagens: Ecologia, aprendizagem socialmente mediada e tradições comportamentais (nº 14/04818-0); Modalidade Projeto Temático; Pesquisador responsável Eduardo Benedicto Ottoni (USP); Investimento R$ 609.276,69.2. Variabilidade de comportamento social de macacos-prego (gênero Cebus): Análise comparativa entre populações para investigação de correlatos fisiológicos (nº 08/55684-3); Modalidade Auxílio à Pesquisa – Regular; Pesquisadora responsável Patrícia Izar (USP); Investimento R$ 186.187,33.
3. Desenvolvimento de novos ligantes/drogas com ação agonística seletiva (biased agonism) para receptores dos sistemas renina-angiotensina e calicreínas-cininas: Novas propriedades e novas aplicações biotecnológicas (nº 12/20148-0); ModalidadeProjeto Temático; Pesquisador responsável Claudio Miguel da Costa Neto (USP); Investimento R$ 3.169.674,21.

Artigos científicos
FALÓTICO, T. et alDigging up food: excavation stone tool use by wild capuchin monkeysScientific Reports. v. 7, n. 1, 6278. 24 jul. 2017.
CARDOSO, R. M. e OTTONI, E. B. The effects of tradition on problem solving by two wild populations of bearded capuchin monkeys in a probing task. Biology Letters. v. 12, n. 11, 20160604. nov. 2016.
FRAGASZY, D. M. et alSynchronized practice helps bearded capuchin monkeys learn to extend attention while learning a traditionPNAS. v. 114, n. 30, p. 7798-805. 25 jul. 2017.
MANGALAM, M., Izar, et alTask-specific temporal organization of percussive movements in wild bearded capuchin monkeysAnimal Behaviour. v. 114, p. 129–137. abr. 2016.
PARREIRAS-E-SILVA, L. T. et alFunctional new world monkey oxytocin forms elicit na altered signaling profile and promotes parental care in ratsPNAS. v. 114, n. 34, p. 9044-49. 22 ago. 2017.
VISALBERGHI, E. et al. Selection of effective stone tools by wild bearded capuchin monkeys (Cebus libidinosus)Current Biology, v. 19, n. 3, p. 213-17. 10 fev. 2009.

Morre na Flórida a orca Tilikum, que inspirou o documentário “Blackfish” (Correio Brasiliense)

A fama internacional de Tilikum começou em 2010, quando, durante uma acrobacia, matou sua treinadora

Postado em 06/01/2017 16:38

A orca Tilikum, estrela do SeaWorld e protagonista do aclamado documentário “Blackfish”, que denunciou o sofrimento dos animais em cativeiro em atrações do gênero, morreu nesta sexta-feira após sofrer uma infecção bacteriana, anunciou o parque temático da Flórida em um comunicado.

A orca macho de 36 anos sofria de “graves problemas de saúde” e ainda se não pode determinar exatamente a causa da morte, segundo a empresa. Entre outros problemas, seus veterinários detectaram uma infecção bacteriana nos pulmões.

“Tilikum tinha, e ainda tem, um lugar especial no coração da família SeaWorld, assim como nos corações de milhões de pessoas ao redor do mundo que inspirou”, disse Joel Manby, presidente do parque de Orlando, no centro da Flórida.

A fama internacional de Tilikum começou em 2010, quando, durante uma acrobacia, matou sua treinadora.

“A vida de Tilikum estará sempre ligada à perda de nossa amiga e colega Dawn Bancheau”, escreveu a empresa no texto publicado em seu site. “Enquanto todos nós sofremos grande tristeza por essa perda, continuamos oferecendo a Tilikum o melhor cuidado possível”.

A morte de Dawn é mencionada no filme de 2013, que ganhou o prêmio Bafta de Melhor Documentário, como um efeito do estresse sofrido por orcas em cativeiro por viver em pequenos tanques e com pouca luz.

A empresa sofreu uma avalanche de críticas após o filme e multiplicaram-se as chamadas para o fechamento desses parques aquáticos.

Finalmente, em março de 2016, SeaWorld anunciou que iria parar a criação de orcas e que sua atual geração desses mamíferos em cativeiro seria a última. A decisão foi aplaudida por organizações de defesa dos animais.

“Tilikum estava perto do fim da expectativa média de vida de baleias orcas do sexo masculino, de acordo com um estudo científico independente”, disse o SeaWorld nesta sexta-feira, relatando ainda que as bactérias que atingiram o animal são encontradas “em hábitats naturais e instalações de zoológicos”.

Com a perda de Tilikum, o SeaWorld tem agora 22 orcas em seus três parques em Orlando, San Antonio (Texas) e San Diego (Califórnia).

Por France Presse

A New Origin Story for Dogs (The Atlantic)

 

June 2, 2016

The first domesticated animals may have been tamed twice.

Katie Salvi

ED YONG

Tens of thousands of years ago, before the internet, before the Industrial Revolution, before literature and mathematics, bronze and iron, before the advent of agriculture, early humans formed an unlikely partnership with another animal—the grey wolf. The fates of our two species became braided together. The wolves changed in body and temperament. Their skulls, teeth, and paws shrank. Their ears flopped. They gained a docile disposition, becoming both less frightening and less fearful. They learned to read the complex expressions that ripple across human faces. They turned into dogs.

Today, dogs are such familiar parts of our lives—our reputed best friends and subject of many a meme—that it’s easy to take them, and what they represent, for granted. Dogs were the first domesticated animals, and their barks heralded the Anthropocene. We raised puppies well before we raised kittens or chickens; before we herded cows, goats, pigs, and sheep; before we planted rice, wheat, barley, and corn; before we remade the world.

“Remove domestication from the human species, and there’s probably a couple of million of us on the planet, max,” says archaeologist and geneticist Greger Larson. “Instead, what do we have? Seven billion people, climate change, travel, innovation and everything. Domestication has influenced the entire earth. And dogs were the first.” For most of human history, “we’re not dissimilar to any other wild primate. We’re manipulating our environments, but not on a scale bigger than, say, a herd of African elephants. And then, we go into partnership with this group of wolves. They altered our relationship with the natural world.”

Larson wants to pin down their origins. He wants to know when, where, and how they were domesticated from wolves. But after decades of dogged effort, he and his fellow scientists are still arguing about the answers. They agree that all dogs, from low-slung corgis to towering mastiffs, are the tame descendants of wild ancestral wolves. But everything else is up for grabs.

Some say wolves were domesticated around 10,000 years ago, while others say 30,000. Some claim it happened in Europe, others in the Middle East, or East Asia. Some think early human hunter-gatherers actively tamed and bred wolves. Others say wolves domesticated themselves, by scavenging the carcasses left by human hunters, or loitering around campfires, growing tamer with each generation until they became permanent companions.

Dogs were domesticated so long ago, and have cross-bred so often with wolves and each other, that their genes are like “a completely homogenous bowl of soup,” Larson tells me, in his office at the University of Oxford. “Somebody goes: what ingredients were added, in what proportion and in what order, to make that soup?” He shrugs his shoulders. “The patterns we see could have been created by 17 different narrative scenarios, and we have no way of discriminating between them.”

The only way of doing so is to look into the past. Larson, who is fast-talking, eminently likable, and grounded in both archaeology and genetics, has been gathering fossils and collaborators in an attempt to yank the DNA out of as many dog and wolf fossils as he can. Those sequences will show exactly how the ancient canines relate to each other and to modern pooches. They’re the field’s best hope for getting firm answers to questions that have hounded them for decades.

And already, they have yielded a surprising discovery that could radically reframe the debate around dog domestication, so that the big question is no longer when it happened, or where, but how many times.

*    *   *

On the eastern edge of Ireland lies Newgrange, a 4,800-year-old monument that predates Stonehenge and the pyramids of Giza. Beneath its large circular mound and within its underground chambers lie many fragments of animal bones. And among those fragments, Dan Bradley from Trinity College Dublin found the petrous bone of a dog.

Press your finger behind your ear. That’s the petrous. It’s a bulbous knob of very dense bone that’s exceptionally good at preserving DNA. If you try to pull DNA out of a fossil, most of it will come from contaminating microbes and just a few percent will come from the bone’s actual owner. But if you’ve got a petrous bone, that proportion can be as high as 80 percent. And indeed, Bradley found DNA galore within the bone, enough to sequence the full genome of the long-dead dog.

Larson and his colleague Laurent Frantz then compared the Newgrange sequences with those of almost 700 modern dogs, and built a family tree that revealed the relationships between these individuals. To their surprise, that tree had an obvious fork in its trunk—a deep divide between two doggie dynasties. One includes all the dogs from eastern Eurasia, such as Shar Peis and Tibetan mastiffs. The other includes all the western Eurasian breeds, and the Newgrange dog.

The genomes of the dogs from the western branch suggest that they went through a population bottleneck—a dramatic dwindling of numbers. Larson interprets this as evidence of a long migration. He thinks that the two dog lineages began as a single population in the east, before one branch broke off and headed west. This supports the idea that dogs were domesticated somewhere in China.

But there’s a critical twist.

The team calculated that the two dog dynasties split from each other between 6,400 and 14,000 years ago.  But the oldest dog fossils in both western and eastern Eurasia are older than that. Which means that when those eastern dogs migrated west into Europe, there were already dogs there.

To Larson, these details only make sense if dogs were domesticated twice.

Here’s the full story, as he sees it. Many thousands of years ago, somewhere in western Eurasia, humans domesticated grey wolves. The same thing happened independently, far away in the east. So, at this time, there were two distinct and geographically separated groups of dogs. Let’s call them Ancient Western and Ancient Eastern. Around the Bronze Age, some of the Ancient Eastern dogs migrated westward alongside their human partners, separating from their homebound peers and creating the deep split in Larson’s tree. Along their travels, these migrants encountered the indigenous Ancient Western dogs, mated with them (doggy style, presumably), and effectively replaced them.

Today’s eastern dogs are the descendants of the Ancient Eastern ones. But today’s western dogs (and the Newgrange one) trace most of their ancestry to the Ancient Eastern migrants. Less than 10 percent comes from the Ancient Western dogs, which have since gone extinct.

This is a bold story for Larson to endorse, not least because he himself has come down hard on other papers suggesting that cows, sheep, or other species were domesticated twice. “Any claims for more than one need to be substantially backed up by a lot of evidence,” he says. “Pigs were clearly domesticated in Anatolia and in East Asia. Everything else is once.” Well, except maybe dogs.

*   *   *

Katie Salvi

Other canine genetics experts think that Larson’s barking up the wrong tree. “I’m somewhat underwhelmed, since it’s based on a single specimen,” says Bob Wayne from the University of California, Los Angeles. He buys that there’s a deep genetic division between modern dogs. But, it’s still possible that dogs were domesticated just once, creating a large, widespread, interbreeding population that only later resolved into two distinct lineages.

In 2013, Wayne’s team compared the mitochondrial genomes (small rings of DNA that sit outside the main set) of 126 modern dogs and wolves, and 18 fossils. They concluded that dogs were domesticated somewhere in Europe or western Siberia, between 18,800 and 32,100 years ago. And genes aside, “the density of fossils from Europe tells us something,” says Wayne. “There are many things that look like dogs, and nothing quite like that in east Asia.”

Peter Savolainen from the KTH Royal Institute of Technology in Stockholm disagrees. By comparing the full genomes of 58 modern wolves and dogs, his team has shown that dogs in southern China are the most genetically diverse in the world. They must have originated there around 33,000 years ago, he says, before a subset of them migrated west 18,000 years later.

That’s essentially the same story that Larson is telling. The key difference is that Savolainen doesn’t buy the existence of an independently domesticated group of western dogs. “That’s stretching the data very much,” he says. Those Ancient Western dogs might have just been wolves, he says. Or perhaps they were an even earlier group of migrants from the east. “I think the picture must seem a bit chaotic,” he says understatedly. “But for me, it’s pretty clear. It must have happened in southern East Asia. You can’t interpret it any other way.”

Except, you totally can. Wayne does (“I’m certainly less dogmatic than Peter,” he says). Adam Boyko from Cornell University does, too: after studying the genes of village dogs—free-ranging mutts that live near human settlements—he argued for a single domestication in Central Asia, somewhere near India or Nepal. And clearly, Larson does as well.

Larson adds that his gene-focused peers are ignoring one crucial line of evidence—bones. If dogs originated just once, there should be a neat gradient of fossils with the oldest ones at the center of domestication and the youngest ones far away from it. That’s not what we have. Instead, archaeologists have found 15,000-year-old dog fossils in western Europe, 12,500-year-old ones in east Asia, and nothing older than 8,000 years in between.

“If we’re wrong, then how on earth do you explain the archaeological data?” says Larson. “Did dogs jump from East Asia to Western Europe in a week, and then go all the way back 4,000 years later?” No. A dual domestication makes more sense. Mietje Genompré, an archaeologist from the Royal Belgian Institute of Natural Sciences, agrees that the bones support Larson’s idea. “For me, it’s very convincing,” she says.

But even Larson is hedging his bets. When I ask him how strong his evidence is, he says, “Like, put a number on it? If was being bold, I’d say it’s a 7 out of 10. We lack the smoking gun.”

Why is this is so hard? Of all the problems that scientists struggle with, why has the origin of dogs been such a bitch to solve?

For starters, the timing is hard to pin down because no one knows exactly how fast dog genomes change. That pace—the mutation rate—underpins a lot of genetic studies. It allows scientists to compare modern dogs and ask: How long ago must these lineages have diverged in order to build up this many differences in their genes? And since individual teams use mutation rate estimates that are wildly different, it’s no wonder they’ve arrive at conflicting answers.

Regardless of the exact date, it’s clear that over thousands of years, dogs have mated with each other, cross-bred with wolves, travelled over the world, and been deliberately bred by humans. The resulting ebb and flow of genes has turned their history into a muddy, turbid mess—the homogeneous soup that Larson envisages.

Wolves provide no clarity. Grey wolves used to live across the entire Northern Hemisphere, so they could have potentially been domesticated anywhere within that vast range (although North America is certainly out). What’s more, genetic studies tell us that no living group of wolves is more closely related to dogs than any other, which means that the wolves that originally gave rise to dogs are now extinct. Sequencing living wolves and dogs will never truly reveal their shrouded past; it’d be, as Larson says, like trying to solve a crime when the culprit isn’t even on the list of suspects.

“The only way to know for sure is to go back in time,” he adds.

*    *   *

Katie Salvi

The study informally known as the Big Dog Project was born of frustration. Back in 2011, Larson was working hard on the origin of domestic pigs, and became annoyed that scientists studying dogs were getting less rigorous papers in more prestigious journals, simply because their subjects were that much more charismatic and media-friendly. So he called up his longstanding collaborator Keith Dobney. “Through gritted teeth, I said: We’re fucking doing dogs. And he said: I’m in.”

Right from the start, the duo realized that studying living dogs would never settle the great domestication debate. The only way to do that was to sequence ancient DNA from fossil dogs and wolves, throughout their range and at different points in history. While other scientists were studying the soup of dog genetics by tasting the finished product, Larson would reach back in time to taste it at every step of its creation, allowing him to definitively reconstruct the entire recipe.

In recent decades, scientists have become increasingly successful at extracting and sequencing strands of DNA from fossils. This ancient DNA has done wonders for our understanding of our own evolution. It showed, for example, how Europe was colonized 40,000 years ago by hunter-gatherers moving up from Africa, then 8,000 years ago by Middle Eastern farmers, and 5,000 years ago by horse-riding herders from the Russian steppes. “Everyone in Europe today is a blend of those three populations,” says Larson, who hopes to parse the dog genome in the same way, by slicing it into its constituent ingredients.

Larson originally envisaged a small project—just him and Dobney analyzing a few fossils. But he got more funding, collaborators, and samples than he expected. “It just kind of metastasized out of all proportion,” he says. He and his colleagues would travel the world, drilling into fossils and carting chips of bone back to Oxford. They went to museums and private collections. (“There was a guy up in York who had a ton of stuff in his garage.”) They grabbed bones from archaeological sites.

The pieces of bone come back to a facility in Oxford called the Palaeo-BARN—the Palaeogenomics and Bioarchaeology Research Network. When I toured the facility with Larson, we wore white overalls, surgical masks, oversoles, and purple gloves, to keep our DNA (and that of our skin microbes) away from the precious fossil samples. Larson called them ‘spacesuits.’ I was thinking ‘thrift-store ninja.’

In one room, the team shoves pieces of bone into a machine that pounds it with a small ball bearing, turning solid shards into fine powder. They then send the powder through a gauntlet of chemicals and filters to pull out the DNA and get rid of everything else. The result is a tiny drop of liquid that contains the genetic essence of a long-dead dog or wolf. Larson’s freezer contains 1,500 such drops, and many more are on the way. “It’s truly fantastic the kind of data that he has gathered,” says Savolainen.

True to his roots in archaeology, Larson isn’t ignoring the bones. His team photographed the skulls of some 7,000 prehistoric dogs and wolves at 220 angles each, and rebuilt them in virtual space. They can use a technique called geometric morphometrics to see how different features on the skulls have evolved over time.

The two lines of evidence—DNA and bones—should either support or refute the double domestication idea. It will also help to clear some confusion over a few peculiar fossils, such as a 36,000 year old skull from Goyet cave in Belgium. Genompré thinks it’s a primitive dog. “It falls outside the variability of wolves: it’s smaller and the snout is different,” she says. Others say it’s too dissimilar to modern dogs. Wayne has suggested that it represents an aborted attempt at domestication—a line of dogs that didn’t contribute to modern populations and is now extinct.

Maybe the Goyet hound was part of Larson’s hypothetical Ancient Western group, domesticated shortly after modern humans arrived in Europe. Maybe it represented yet another separate flirtation with domestication. All of these options are on the table, and Larson thinks he has the data to tell them apart. “We can start putting numbers on the difference between dogs and wolves,” he says. “We can say this is what all the wolves at this time period look like; does the Goyet material fall within that realm, or does it look like dogs from later on?”

Larson hopes to have the first big answers within six to twelve months. “I think it’ll clearly show that some things can’t be right, and will narrow down the number of hypotheses,” says Boyko. “It may narrow it down to one but I’m not holding my breath on that.” Wayne is more optimistic. “Ancient DNA will provide much more definitive data than we had in the past,” he says. “[Larson] convinced everyone of that. He’s a great diplomat.”

Indeed, beyond accumulating DNA and virtual skulls, Larson’s greatest skill is in gathering collaborators. In 2013, he rounded up as many dog researchers as he could and flew them to Aberdeen, so he could get them talking. “I won’t say there was no tension,” he says. “You go into a room with someone who has written something that sort of implies you aren’t doing very good science… there will be tension. But it went away very quickly. And, frankly: alcohol.”

“Everyone was like: You know what? If I’m completely wrong and I have to eat crow on this, I don’t give a shit. I just want to know.”

A single-celled organism capable of learning (Science Daily)

Date:
April 27, 2016
Source:
CNRS
Summary:
For the first time, scientists have demonstrated that an organism devoid of a nervous system is capable of learning. Biologists have succeeded in showing that a single-celled organism, the protist, is capable of a type of learning called habituation. This discovery throws light on the origins of learning ability during evolution, even before the appearance of a nervous system and brain. It may also raise questions as to the learning capacities of other extremely simple organisms such as viruses and bacteria.

The slime mold Physarum polycephalum (diameter: around 10 centimeters), made up of a single cell, was here cultivated in the laboratory on agar gel. Credit: Audrey Dussutour (CNRS)

For the first time, scientists have demonstrated that an organism devoid of a nervous system is capable of learning. A team from the Centre de Recherches sur la Cognition Animale (CNRS/Université Toulouse III — Paul Sabatier) has succeeded in showing that a single-celled organism, the protist Physarum polycephalum, is capable of a type of learning called habituation. This discovery throws light on the origins of learning ability during evolution, even before the appearance of a nervous system and brain. It may also raise questions as to the learning capacities of other extremely simple organisms such as viruses and bacteria. These findings are published in the Proceedings of the Royal Society B on 27 April 2016.

An ability to learn, and memory are key elements in the animal world. Learning from experiences and adapting behavior accordingly are vital for an animal living in a fluctuating and potentially dangerous environment. This faculty is generally considered to be the prerogative of organisms endowed with a brain and nervous system. However, single-celled organisms also need to adapt to change. Do they display an ability to learn? Bacteria certainly show adaptability, but it takes several generations to develop and is more a result of evolution. A team of biologists thus sought to find proof that a single-celled organism could learn. They chose to study the protist, or slime mold, Physarum polycephalum, a giant cell that inhabits shady, cool areas[1] and has proved to be endowed with some astonishing abilities, such as solving a maze, avoiding traps or optimizing its nutrition[2]. But until now very little was known about its ability to learn.

During a nine-day experiment, the scientists thus challenged different groups of this mold with bitter but harmless substances that they needed to pass through in order to reach a food source. Two groups were confronted either by a “bridge” impregnated with quinine, or with caffeine, while the control group only needed to cross a non-impregnated bridge. Initially reluctant to travel through the bitter substances, the molds gradually realized that they were harmless, and crossed them increasingly rapidly — behaving after six days in the same way as the control group. The cell thus learned not to fear a harmless substance after being confronted with it on several occasions, a phenomenon that the scientists refer to as habituation. After two days without contact with the bitter substance, the mold returned to its initial behavior of distrust. Furthermore, a protist habituated to caffeine displayed distrustful behavior towards quinine, and vice versa. Habituation was therefore clearly specific to a given substance.

Habituation is a form of rudimentary learning, which has been characterized in Aplysia (an invertebrate also called sea hare)[3]. This form of learning exists in all animals, but had never previously been observed in a non-neural organism. This discovery in a slime mold, a distant cousin of plants, fungi and animals that appeared on Earth some 500 million years before humans, improves existing understanding of the origins of learning, which markedly preceded those of nervous systems. It also offers an opportunity to study learning types in other very simple organisms, such as viruses or bacteria.

[1] This single cell, which contains thousands of nuclei, can cover an area of around a square meter and moves within its environment at speeds that can reach 5 cm per hour.

[2] See “Even single-celled organisms feed themselves in a ‘smart’ manner.” https://www.sciencedaily.com/releases/2010/02/100210164712.htm

[3] Mild tactile stimulation of the animal’s siphon normally causes the defensive reflex of withdrawing the branchiae. If the harmless tactile stimulation is repeated, this reflex diminishes and finally disappears, thus indicating habituation.


Journal Reference:

  1. Romain P. Boisseau, David Vogel, Audrey Dussutour. Habituation in non-neural organisms: evidence from slime mouldsProceedings of the Royal Society B: Biological Sciences, 2016; 283 (1829): 20160446 DOI: 10.1098/rspb.2016.0446

What I Learned From Tickling Apes (New York Times)

Laughter? Now wait a minute! A real scientist should avoid any and all anthropomorphism, which is why hard-nosed colleagues often ask us to change our terminology. Why not call the ape’s reaction something neutral, like, say, vocalized panting? That way we avoid confusion between the human and the animal.

The term anthropomorphism, which means “human form,” comes from the Greek philosopher Xenophanes, who protested in the fifth century B.C. against Homer’s poetry because it described the gods as though they looked human. Xenophanes mocked this assumption, reportedly saying that if horses had hands they would “draw their gods like horses.” Nowadays the term has a broader meaning. It is typically used to censure the attribution of humanlike traits and experiences to other species. Animals don’t have “sex,” but engage in breeding behavior. They don’t have “friends,” but favorite affiliation partners.

Given how partial our species is to intellectual distinctions, we apply such linguistic castrations even more vigorously in the cognitive domain. By explaining the smartness of animals either as a product of instinct or simple learning, we have kept human cognition on its pedestal under the guise of being scientific. Everything boiled down to genes and reinforcement. To think otherwise opened you up to ridicule, which is what happened to Wolfgang Köhler, the German psychologist who, a century ago, was the first to demonstrate flashes of insight in chimpanzees.

Köhler would put a banana outside the enclosure of his star performer, Sultan, while giving him sticks that were too short to reach the fruit through the bars. Or he would hang a banana high up and spread boxes around, none of which were tall enough to reach the fruit. At first, Sultan would jump or throw things at the banana or drag a human by the hand toward it, hoping to use him as a footstool. If this failed, he would sit around without doing anything, pondering the situation, until he might hit on a solution. He’d jump up suddenly to put one bamboo stick inside another, making a longer stick. He’d also stack boxes to build a tower tall enough to attain his reward. Köhler described this moment as the “aha! experience,” not unlike Archimedes running through the streets shouting “Eureka!”

According to Köhler, Sultan showed insight by combining what he knew about boxes and sticks to produce a brand-new action sequence to take care of his problem. It all took place in his head, without prior rewards for his eventual solution. That animals may show mental processes closer to thinking than learning was so unsettling, though, that still today Köhler’s name is hissed rather than spoken in some circles. Naturally, one of his critics argued that the attribution of reasoning to animals was an “overswing of the theoretical pendulum” back “toward anthropomorphism.”

We still hear this argument, not so much for tendencies that we consider animalistic (everyone is free to speak of aggression, violence and territoriality in animals) but rather for traits that we like in ourselves. Accusations of anthropomorphism are about as big a spoiler in cognitive science as suggestions of doping are of athletic success. The indiscriminate nature of these accusations has been detrimental to cognitive science, as it has kept us from developing a truly evolutionary view. In our haste to argue that animals are not people, we have forgotten that people are animals, too.

This doesn’t mean that anything goes. Humans are incredibly eager to project feelings and experiences onto animals, often doing so uncritically. We go to beach hotels to swim with dolphins, convinced that the animals must love it as much as we do. We think that our dog feels guilt or that our cat is embarrassed when she misses a jump. Lately, people have fallen for the suggestion that Koko, the signing gorilla in California, is worried about climate change, or that chimpanzees have religion. As soon as I hear such claims, I contract my corrugator muscles (causing a frown) and ask for the evidence. Yes, dolphins have smiley faces, but since this is an immutable part of their visage, it fails to tell us anything about how they feel. Yes, dogs hide under the table when they have done something wrong, yet the most likely explanation is that they fear trouble.

Gratuitous anthropomorphism is distinctly unhelpful. However, when experienced field workers who follow apes around in the tropical forest tell me about the concern chimpanzees show for an injured companion, bringing her food or slowing down their walking pace, or report how adult male orangutans in the treetops vocally announce which way they expect to travel the next morning, I am not averse to speculations about empathy or planning. Given everything we know from controlled experiments in captivity, such as the ones I conduct myself, these speculations are not far-fetched.

To understand the resistance to cognitive explanations, I need to mention a third ancient Greek: Aristotle. The great philosopher put all living creatures on a vertical Scala Naturae, which runs from humans (closest to the gods) down toward other mammals, with birds, fish, insects and mollusks near the bottom. Comparisons up and down this vast ladder have been a popular scientific pastime, but all we have learned from them is how to measure other species by our standards. Keeping Aristotle’s scale intact, with humans on top, has been the unfailing goal.

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But think about it: How likely is it that the immense richness of nature fits on a single dimension? Isn’t it more likely that each animal has its own cognition, adapted to its own senses and natural history? It makes no sense to compare our cognition with one that is distributed over eight independently moving arms, each with its own neural supply, or one that enables a flying organism to catch mobile prey by picking up the echoes of its own shrieks. Clark’s nutcrackers (members of the crow family) recall the location of thousands of seeds that they have hidden half a year before, while I can’t even remember where I parked my car a few hours ago. Anyone who knows animals can come up with a few more cognitive comparisons that are not in our favor. Instead of a ladder, we are facing an enormous plurality of cognitions with many peaks of specialization. Somewhat paradoxically, these peaks have been called “magic wells” because the more scientists learn about them, the deeper the mystery gets.

We now know, for example, that some crows excel at tool use. In an aviary at Oxford University in 2002, a New Caledonian crow named Betty tried to pull a little bucket with a piece of meat out of a transparent vertical pipe. All she had to work with was a straight metal wire, which didn’t do the trick. Undeterred, Betty used her beak to bend the straight wire into a hook to pull up the bucket. Since no one had taught Betty to do so, it was seen as an example of insight. Apart from dispelling the “birdbrain” notion with which birds are saddled, Betty achieved instant fame by offering proof of tool making outside the primate order. Since this capacity has by now been confirmed by other studies, including one on a cockatoo, we can safely do away with the 1949 book “Man the Tool-Maker” by the British anthropologist Kenneth Oakley, which declared tool fabrication humanity’s defining characteristic. Corvids are a technologically advanced branch on the tree of life with skills that often match those of primates like us.

Convergent evolution (when similar traits, like the wings of birds, bats and insects, appear independently in separate evolutionary branches) allows cognitive capacities to pop up at the most unexpected places, such as face recognition in paper wasps or deceptive tactics in cephalopods. When the males of some cuttlefish species are interrupted by a rival during courtship, they may trick the latter into thinking there is nothing to worry about. On the side of his body that faces his rival, the male adopts the coloring of a female, so that the other believes he is looking at two females. But the courting male keeps his original coloring on the female’s side of his body in order to keep her attention. This two-faced tactic, known as dual-gender signaling, suggests tactical skills of an order no one had ever suspected in a species so low on the natural scale. But of course, talk of “high” and “low” is anathema to biologists, who see every single organism as exquisitely adapted to its own environment.

Now let us return to the accusation of anthropomorphism that we hear every time a new discovery comes along. This accusation works only because of the premise of human exceptionalism. Rooted in religion but also permeating large areas of science, this premise is out of line with modern evolutionary biology and neuroscience. Our brains share the same basic structure with other mammals — no different parts, the same old neurotransmitters.

Brains are in fact so similar across the board that we study fear in the rat’s amygdala to treat human phobias. This doesn’t mean that the planning by an orangutan is of the same order as me announcing an exam in class and my students preparing for it, but deep down there is continuity between both processes. This applies even more to emotional traits.

This is why science nowadays often starts from the opposite end, assuming continuity between humans and animals, while shifting the burden of proof to those who insist on differences. Anyone who asks me to believe that a tickled ape, who almost chokes on his hoarse giggles, is in a different state of mind than a tickled human child has his work cut out for him.

In order to drive this point home, I invented the term “anthropodenial,” which refers to the a priori rejection of humanlike traits in other animals or animallike traits in us. Anthropomorphism and anthropodenial are inversely related: The closer another species is to us, the more anthropomorphism assists our understanding of this species and the greater will be the danger of anthropodenial. Conversely, the more distant a species is from us, the greater the risk that anthropomorphism proposes questionable similarities that have come about independently. Saying that ants have “queens,” “soldiers” and “slaves” is mere anthropomorphic shorthand without much of a connection to the way human societies create these roles.

THE key point is that anthropomorphism is not nearly as bad as people think. With species like the apes — aptly known as “anthropoids” (humanlike) — anthropomorphism is in fact a logical choice. After a lifetime of working with chimpanzees, bonobos and other primates, I feel that denial of the similarities is a greater problem than accepting them. Relabeling a chimpanzee kiss “mouth-to-mouth contact” obfuscates the meaning of a behavior that apes show under the same circumstances as humans, such as when they greet one another or reconcile after a fight. It would be like assigning Earth’s gravity a different name than the moon’s, just because we think Earth is special.

Unjustified linguistic barriers fragment the unity with which nature presents us. Apes and humans did not have enough time to independently evolve almost identical behavior under similar circumstances. Think about this the next time you read about ape planning, dog empathy or elephant self-awareness. Instead of denying these phenomena or ridiculing them, we would do better to ask “why not?”

One reason this whole debate is as heated as it is relates to its moral implications. When our ancestors moved from hunting to farming, they lost respect for animals and began to look at themselves as the rulers of nature. In order to justify how they treated other species, they had to play down their intelligence and deny them a soul. It is impossible to reverse this trend without raising questions about human attitudes and practices. We can see this process underway in the halting of biomedical research on chimpanzees and the opposition to the use of killer whales for entertainment.

Increased respect for animal intelligence also has consequences for cognitive science. For too long, we have left the human intellect dangling in empty evolutionary space. How could our species arrive at planning, empathy, consciousness and so on, if we are part of a natural world devoid of any and all steppingstones to such capacities? Wouldn’t this be about as unlikely as us being the only primates with wings?

Evolution is a gradual process of descent with modification, whether we are talking about physical or mental traits. The more we play down animal intelligence, the more we ask science to believe in miracles when it comes to the human mind. Instead of insisting on our superiority in every regard, let’s take pride in the connections.

There is nothing wrong with the recognition that we are apes — smart ones perhaps, but apes nonetheless. As an ape lover, I can’t see this comparison as insulting. We are endowed with the mental powers and imagination to get under the skin of other species. The more we succeed, the more we will realize that we are not the only intelligent life on earth.

Frans de Waal, a primatologist and professor of psychology at Emory University, is the author, most recently, of “Are We Smart Enough to Know How Smart Animals Are?” from which this essay is adapted.

A version of this op-ed appears in print on April 10, 2016, on page SR1 of the New York edition with the headline: What I Learned Tickling Apes. 

Todo inocente é um fdp? (El País)

Como se mover num mundo em que se tornou impossível não enxergar o mal que se pratica

ELIANE BRUM

29 FEV 2016 – 14:44 BRT

O golfinho que pode ter morrido por desidratação tirando selfie com turistas na Argentina.

O golfinho que pode ter morrido por desidratação tirando selfie com turistas na Argentina.

Lembro uma cena do primeiro filme da trilogia Matrix, ícone do final do século 20. Os membros da resistência eram aqueles que, em algum momento, enxergaram que a vida cotidiana era só uma trama, um programa de computador, uma ilusão. A realidade era um deserto em que os rebeldes lutavam contra “as máquinas” num mundo sem beleza ou gosto. Fazia-se ali uma escolha: tomar a pílula azul ou a vermelha. Quem escolhesse a vermelha, deixaria de acreditar no mundo como nos é dado para ver e passaria a ser confrontado com a verdade da condição humana.

Na cena que aqui me interessa recordar, um traidor da resistência negocia os termos de sua rendição enquanto se delicia com um suculento filé. Ele sabe que o filé não existe de fato, que é um programa de computador que o faz ver, sentir o cheiro e o gosto da carne, mas se esbalda. Entregaria sua alma às máquinas em troca de voltar na melhor posição – rico e famoso – ao mundo das ilusões. Delataria os companheiros se a ele fosse devolvida a inocência sobre a realidade do real. Sacrifica a luta, os amigos e a ética em troca de um desejo: voltar a ser cego. Ou voltar a acreditar no filé.

A frase exata, pronunciada enquanto olha para um naco da carne espetada no garfo, é: “Eu sei que esse filé não existe. Sei que, quando o coloco na boca, a Matrix diz ao meu cérebro que ele é suculento e delicioso”. Faz uma pausa: “Depois de nove anos, sabe o que percebi? A ignorância é maravilhosa”.

Naquela época, véspera da virada do milênio, o filme deu ao público uma porta para o debate filosófico sobre o real. Tomar a pílula vermelha logo tornou-se uma metáfora para quem escolhe enxergar a Matrix – ou enxergar para além das aparências. Desde então, nestes últimos anos de corrosão acelerada das ilusões, penso que a escolha se tornou bem mais complicada.

A ilusão, que desempenhou um papel estrutural na constituição subjetiva da nossa espécie, pode já não estar ao nosso alcance

Talvez o mal-estar do nosso tempo seja o de que já não é possível escolher entre a pílula azul e a vermelha – ou entre continuar cego ou começar a enxergar o que está por trás da trama dos dias. O mal-estar se deve ao fato de que talvez já não exista a pílula azul – ou já não seja mais possível a ilusão, esta que desempenhou um papel estrutural na constituição subjetiva da nossa espécie ao longo dos milênios.

Se fosse um de nós o membro da resistência disposto a trair os companheiros, a negociar a rendição com as máquinas diante de um suculento filé num restaurante, aqui, agora, e não mais no final dos anos 90, o dilema poderia sofrer um deslocamento. O drama não seria enxergar o filé como filé, no sentido de poder acreditar que ele existe, assim como acreditar que o restaurante existe e que o cenário a que chamamos de mundo existe tal qual está diante dos nossos olhos.

Não. O dilema atual pode ser também este, mas só na medida em que também é outro. O drama é que acreditamos no filé, sabemos que ele existe e sabemos que é gostoso. Desejamos o filé, nos lambuzamos dele e temos prazer com ele. Ao olhar para ele, porém, não enxergamos apenas “o deserto do real”, mas algo muito mais encarnado e cada vez mais inescapável: enxergamos o boi.

É terrível enxergar o boi. E, como os mais sensíveis já descobriram, é impossível deixar de enxergá-lo. Nossa superpopulação de humanos extrapolou a lógica dos vivos, matar para comer. E impôs a escravização e a tortura cotidiana de outras espécies. Milhões de bois, galinhas e porcos nascem apenas para nos alimentar em campos de concentração aos quais damos nomes mais palatáveis. São sacrificados em holocaustos diários sem que nem mesmo tenham tido uma vida.

Animais confinados, presos, às vezes sem sequer poder se mover por uma existência inteira. Criamos profissões capazes de reconhecer em segundos se um pinto é macho ou fêmea para separar as fêmeas que viverão espremidas, muitas vezes sem conseguir sequer abrir as asas, botando ovos e depois virando bandejas no supermercado e jogar os machos para serem moídos ainda vivos no triturador de lixo. Escravidão e tortura/sacrifício e lixo, estes são os destinos que determinamos aos frangos.

Somos os nazistas das outras espécies – e produzimos holocaustos cotidianos

Somos os nazistas das outras espécies. E, se antes era possível ignorar, desqualificando a questão como algo menor ou coisa de “adoradores de alface”, a internet e a disseminação de informações tornaram impossível não enxergar o olho do boi. Ao olhar para o filé, o olho do boi nos olha de volta. O olho vidrado de quem está aterrorizado porque pressente que caminha no corredor da morte, o boi que se caga de medo enquanto é obrigado a dar o passo para o sacrifício, o boi que tenta escapar, mas não encontra saída. O olho do boi alcança até gente como eu, que pode ser colocada na categoria “adoradores de churrasco”.

A publicidade do século 20 perdeu a ressonância em tempos de internet. Porque a ilusão já não é possível. Nada era mais puro do que o leite branco tirado de uma vaquinha no pasto. Era fácil acreditar na imagem bucólica do alimento saudável. Nosso leite vinha do paraíso, de nosso passado rural perdido, da vida nos bosques de Walden. Assim como a longa série de produtos dele originados, como queijo, iogurte e manteiga.

Mas a vaca da imagem não existe. A real é a vaca que nasce em cativeiro, filha de outra escrava. A vaca que quase não se move, cuja existência consiste numa longa série de estupros por instrumentos que se enfiam pelo seu corpo para fecundá-la com o sêmen de outro escravo. Então ela engravida e engravida e engravida de bezerros que dela serão sequestrados para virar filés, para que suas tetas sigam dando leite delas tirados por outras máquinas. E, como sabemos disso, o leite que chega à nossa mesa já não pode mais ser branco, mas vermelho do horror da vaca cujo corpo virou um objeto, a vaca para quem cada dia é tortura, estupro e escravidão.

Para não beber sangue procuramos nas prateleiras leites à base de vegetais. Vegetais não gritam. Soja, apenas um dos tantos exemplos. Bifes de soja, hambúrgueres de soja, linguiças de soja, leite de soja. Mas como ignorar o desmatamento, a destruição de ecossistemas inteiros e com eles toda a vida que lá havia? Como ignorar que a soja pode ter sido plantada em terra indígena e que, enquanto ela vira mercadoria no supermercado, jovens Guarani Kaiowá se enforcam porque já não sabem como viver? Já não é possível fingir que não enxergamos isso. Assim, nem os veganos mais radicais podem se salvar do pecado original.

Os mais sensíveis sentem a textura de suas roupas e sabem que são costuradas com carne humana

Olhamos para nossas roupas e horrorizados sabemos que em algum lugar da linha globalizada de produção há nelas o sangue de crianças, homens e mulheres em regime de trabalho análogo à escravidão. Como o casal que morreu abraçado na fábrica de Bangladesh, gerando a fotografia que comoveu o mundo mas não eliminou o horror que seguiu em escala industrial. Ou mesmo de um imigrante boliviano enfiado num quarto insalubre trabalhando horas e horas por quase nada bem aqui ao lado. Mas os mais sensíveis sentem a textura de suas roupas e sabem que são costuradas com carne humana. E já não sabem como vesti-las. Nem sabem como dar brinquedos para seus filhos porque sabem que os bonecos, os carrinhos, os castelos e os dinossauros contêm neles o sangue das crianças sem infância, ou o de suas mães e pais.

Já não é possível levar crianças a zoológicos ou aquários porque sabemos que a única educação próxima da verdade que receberiam ali é a do horror a que os animais são submetidos para serem exibidos, por melhor que seja a imitação de seu habitat. Lembro uma reportagem que fui fazer num zoológico, planejada para ser divertida, e só pude contar, entre outros horrores, que o babuíno chamado Beto era mantido à custa de Valium, para evitar que arrancasse pedaços do próprio corpo. Mesmo dopado jogava-se contra as grades, atirava fezes nos visitantes e espancava a companheira. Pinky, a elefanta, vivia só. Seus dois companheiros tinham morrido ao cair no fosso tentando escapar do cativeiro. Sabemos hoje que os golfinhos e as baleias dos shows acrobáticos são escravos brutalizados para servir de entretenimento a humanos. E, desde que sabemos, aqueles que gozam com esses espetáculos de morte podem se descobrir não mais como famílias felizes num momento de lazer, como nas imagens dos folhetos publicitários, mas como hordas de sádicos.

No simples ato de acender a luz já existe a consciência de que estamos destruindo o mundo de alguém e de que nada mais será simples. Neste momento, para ficar apenas num exemplo, dezenas de milhares já perderam suas casas no rio Xingu, na Amazônia, para a operação da Hidrelétrica de Belo Monte. Povos indígenas que vivem na região atingida já não conseguem suportar o aumento exponencial de mosquitos desde que o lago da usina começou a encher, alterando o ecossistema e dizimando culturas, no que já foi denunciado pelo Ministério Público Federal como etnocídio. Os impactos mal começaram e, em menos de três meses, mais de 16 toneladas de peixes morreram. E talvez também esteja chegando ao fim o tempo em que ainda é aceitável contar vidas por toneladas, mesmo que seja a vida de peixes. Ou a morte de peixes. Um dedo no interruptor e uma cadeia de mortes. E agora também já sabemos disso.

Ao pedir um café e um pão com manteiga na padaria, nos implicamos numa cadeia de horrores

O tempo das ilusões acabou. Nenhum ato do nosso cotidiano é inocente. Ao pedir um café e um pão com manteiga na padaria, nos implicamos numa cadeia de horrores causados a animais e a humanos envolvidos na produção. Cada ato banal implica uma escolha ética – e também uma escolha política.

A descrição das atrocidades que cometemos rotineiramente pode aqui seguir por milhares de caracteres. Comemos, vestimos, nos entretemos, transportamos e nos transportamos à custa da escravidão, da tortura e do sacrifício de outras espécies e também dos mais frágeis da nossa própria espécie. Somos o que de pior aconteceu ao planeta e a todos que o habitam. A mudança climática já anuncia que não apenas tememos a catástrofe, mas nos tornamos a catástrofe. Desta vez, não só para todos os outros, mas também para nós mesmos.

Já não é possível a pílula azul – ou já não é possível à adesão às ilusões. Há várias implicações profundas numa época em que o conhecimento não liberta, mas condena. A começar, talvez, pela pergunta: quem é o inocente num mundo em que a inocência já não é possível? Seria o inocente o pior humano de todos? Seria o inocente um psicopata?

O que seremos nós, subjetivamente, agora que estamos condenados a enxergar? As redes sociais têm nos dado algumas pistas. O que a internet fez foi arrancar da humanidade as ilusões sobre si mesma. O cotidiano nas redes sociais nos mostrou a verdade que sempre esteve lá, mas era protegida – ou mediada – pelo mundo das aparências. Sobre isso já escrevi um artigo, chamado A boçalidade do mal, que pode ser lido aqui. As implicações de perder este véu tão arduamente tecido são profundas e recém começam a ser investigadas. O impacto sobre a subjetividade estrutural de nossa espécie é tremendo, exatamente porque é estrutural e desabou num espaço de tempo muito curto, quase num soluço.

Já não é mais possível pensar apenas em humanos quando se aborda o tema dos direitos

O que faremos diante da impossibilidade da pílula azul, a que garantia as ilusões? A ridicularização daqueles que levantam esse tema ainda é um caminho, mas convencem menos que no passado. Também a piada se torna anacrônica. As interrogações vêm mudando, e já não é possível afirmar, sem revelar considerável ignorância, inclusive sobre a ciência produzida, que os animais não têm vida mental nem emocional, são “irracionais”. Ou, lembrando um argumento religioso, “que não têm alma”. Toda a ideologia que um dia justificou a escravidão de humanos, até que foi questionada, derrubada e transformada numa mancha de crime e vergonha na história da humanidade, passou a ser confrontada também com relação aos animais.

Cada vez mais as outras espécies começam a ser vistas como diferentes – e não mais como inferiores. Assim, o que se coloca no campo da ética são questões fascinantes e muito mais espinhosas. Mesmo o termo “direitos humanos” passa a ser questionável, porque pensar apenas em “humanos” já não é mais possível. No momento em que nos tornamos a própria definição de catástrofe, o conceito de “espécie”, em sua expressão cultural, se desloca. Outras formas de compreender e nomear o lugar dos humanos ganham espaço no horizonte filosófico e no exercício da política.

Resta o cinismo, sempre o último reduto. Dizer que, diante de mais de 7 bilhões de seres humanos ocupando o planeta e crescendo, não há outra maneira a não ser comer e vestir exploração, escravidão e tortura é a afirmação mais óbvia. É a afirmação expandida usada para todas as desigualdades de direitos. Desde que não seja eu – ou os meus – os sacrificados, tudo bem.

Vale a pena dedicar um parágrafo aos cínicos, essa categoria que prolifera com o ímpeto de um Aedes aegypti no Brasil e no mundo. O cínico é aquele que olha com calculado enfado para todos os outros, porque ele acredita que entende o mundo como ele de fato é. Ele é o que sabe das coisas, o único esperto. Todos os outros são tolinhos com ideias irreais. O cínico é aquele que deixa o mundo como está. Mas talvez, neste momento, o cínico seja justamente o inocente. Sua inocência consiste em acreditar que a pílula azul ainda está disponível.

Como ser ético num mundo sem ilusões, em que cada ato implica na tortura e no sacrifício de um outro?

Há um preço para enxergar e, mesmo assim, assumir o extermínio cotidiano como dado, como parte intrínseca da condição de ser um humano. Nem toda a crescente gourmetização da comida, nem todas as narrativas ficcionais que contam uma história idílica sobre a origem daquele produto, nada ocultará esse preço. E nada reduzirá seu impacto subjetivo. Não é fácil viver na pele do algoz. Não é simples viver sabendo-se. Aquele que se olha no espelho e se enxerga carregará essa autoimagem consigo. E se tornará algo que já não é mais o mesmo.

Há uma imagem recente que pode dar algumas pistas sobre esse caminho. Numa praia da Argentina, um golfinho foi carregado por turistas. Alguns dizem que ainda estava vivo, outros que já estava morto. Vivo ou morto, os turistas preocuparam-se apenas com tirar selfies para postar nas redes sociais. O site de humor Sensacionalista postou: “Golfinho morre ao ser retirado do mar para turistas fazerem selfie e Deus anuncia recall do ser humano”.

Ainda assim, quem se horrorizou com a falta de horror alheia, à noite seguiu diante do olho do boi. O que fazer diante do olho do boi? Como ser ético num mundo sem ilusões, em que cada ato implica na tortura e no sacrifício de um outro, humano e não humano? Se somos os nazistas das outras espécies, quando não da mesma, aceitar que assim é não seria se tornar um Eichmann, o nazista julgado em Jerusalém que alegou apenas cumprir ordens, o homem tão banalmente ordinário que inspirou a filósofa Hannah Arendt a criar o conceito da “banalidade do mal”? Não seríamos, aos olhos do boi, todos Eichmann, justificando-nos pelo senso comum de que assim é e se faz o que é preciso para sobreviver? Se sim, o que implica viver assumidamente nesta pele?

Talvez estejamos, como espécie que se pensa, diante de um dos maiores dilemas éticos da nossa história. Sem poder optar pela pílula azul, a das ilusões, condenados à pílula vermelha, a que nos obriga a enxergar, como construir uma escolha que volte a incluir a ética? Como não paralisar diante do espelho, reduzidos ou ao horror ou ao cinismo, eliminando a possibilidade de transformação? Como nos mover?

Diante do filé que desejamos e do olho boi que nos interroga, há pelo menos uma hipótese cada vez mais forte: o inocente é um assassino.

Army ants’ ‘living’ bridges span collective intelligence, ‘swarm’ robotics (Science Daily)

Date: November 24, 2015

Source: Princeton University

Summary: Researchers report for the first time that the ‘living’ bridges army ants of the species Eciton hamatum build with their bodies are more sophisticated than scientists knew. The ants automatically assemble with a level of collective intelligence that could provide new insights into animal behavior and even help in the development of intuitive robots that can cooperate as a group.


Researchers from Princeton University and the New Jersey Institute of Technology report for the first time that the “living” bridges army ants of the species Eciton hamatum (pictured) build with their bodies are more sophisticated than scientists knew. The ants automatically assemble with a level of collective intelligence that could provide new insights into animal behavior and even help in the development of intuitive robots that can cooperate as a group. Credit: Courtesy of Matthew Lutz, Princeton University, and Chris Reid, University of Sydney

 Columns of workers penetrate the forest, furiously gathering as much food and supplies as they can. They are a massive army that living things know to avoid, and that few natural obstacles can waylay. So determined are these legions that should a chasm or gap disrupt the most direct path to their spoils they simply build a new path — out of themselves.

Without any orders or direction, individuals from the rank and file instinctively stretch across the opening, clinging to one another as their comrades-in-arms swarm across their bodies. But this is no force of superhumans. They are army ants of the species Eciton hamatum, which form “living” bridges across breaks and gaps in the forest floor that allow their famously large raiding swarms to travel efficiently.

Researchers from Princeton University and the New Jersey Institute of Technology (NJIT) report for the first time that these structures are more sophisticated than scientists knew. The ants exhibit a level of collective intelligence that could provide new insights into animal behavior and even help in the development of intuitive robots that can cooperate as a group, the researchers said.

Ants of E. hamatum automatically form living bridges without any oversight from a “lead” ant, the researchers report in the journal Proceedings of the National Academy of the Sciences. The action of each individual coalesces into a group unit that can adapt to the terrain and also operates by a clear cost-benefit ratio. The ants will create a path over an open space up to the point when too many workers are being diverted from collecting food and prey.

“These ants are performing a collective computation. At the level of the entire colony, they’re saying they can afford this many ants locked up in this bridge, but no more than that,” said co-first author Matthew Lutz, a graduate student in Princeton’s Department of Ecology and Evolutionary Biology.

“There’s no single ant overseeing the decision, they’re making that calculation as a colony,” Lutz said. “Thinking about this cost-benefit framework might be a new insight that can be applied to other animal structures that people haven’t thought of before.”

The research could help explain how large groups of animals balance cost and benefit, about which little is known, said co-author Iain Couzin, a Princeton visiting senior research scholar in ecology and evolutionary biology, and director of the Max Planck Institute for Ornithology and chair of biodiversity and collective behavior at the University of Konstanz in Germany.

Previous studies have shown that single creatures use “rules of thumb” to weigh cost-and-benefit, said Couzin, who also is Lutz’s graduate adviser. This new work shows that in large groups these same individual guidelines can eventually coordinate group-wide, he said — the ants acted as a unit although each ant only knew its immediate circumstances.

“They don’t know how many other ants are in the bridge, or what the overall traffic situation is. They only know about their local connections to others, and the sense of ants moving over their bodies,” Couzin said. “Yet, they have evolved simple rules that allow them to keep reconfiguring until, collectively, they have made a structure of an appropriate size for the prevailing conditions.

“Finding out how sightless ants can achieve such feats certainly could change the way we think of self-configuring structures in nature — and those made by man,” he said.

Ant-colony behavior has been the basis of algorithms related to telecommunications and vehicle routing, among other areas, explained co-first author Chris Reid, a postdoctoral research associate at the University of Sydney who conducted the work while at NJIT. Ants exemplify “swarm intelligence,” in which individual-level interactions produce coordinated group behavior. E. hamatum crossings assemble when the ants detect congestion along their raiding trail, and disassemble when normal traffic has resumed.

Previously, scientists thought that ant bridges were static structures — their appearance over large gaps that ants clearly could not cross in midair was somewhat of a mystery, Reid said. The researchers found, however, that the ants, when confronted with an open space, start from the narrowest point of the expanse and work toward the widest point, expanding the bridge as they go to shorten the distance their compatriots must travel to get around the expanse.

“The amazing thing is that a very elegant solution to a colony-level problem arises from the individual interactions of a swarm of simple worker ants, each with only local information,” Reid said. “By extracting the rules used by individual ants about whether to initiate, join or leave a living structure, we could program swarms of simple robots to build bridges and other structures by connecting to each other.

“These robot bridges would exhibit the beneficial properties we observe in the ant bridges, such as adaptability to local conditions, real-time optimization of shape and position, and rapid construction and deconstruction without the need for external building materials,” Reid continued. “Such a swarm of robots would be especially useful in dangerous and unpredictable conditions, such as natural disaster zones.”

Radhika Nagpal, a professor of computer science at Harvard University who studies robotics and self-organizing biological systems, said that the findings reveal that there is “something much more fundamental about how complex structures are assembled and adapted in nature, and that it is not through a supervisor or planner making decisions.”

Individual ants adjusted to one another’s choices to create a successful structure, despite the fact that each ant didn’t necessarily know everything about the size of the gap or the traffic flow, said Nagpal, who is familiar with the research but was not involved in it.

“The goal wasn’t known ahead of time, but ‘emerged’ as the collective continually adapted its solution to the environmental factors,” she said. “The study really opens your eyes to new ways of thinking about collective power, and has tremendous potential as a way to think about engineering systems that are more adaptive and able to solve complex cost-benefit ratios at the network level just through peer-to-peer interactions.”

She compared the ant bridges to human-made bridges that automatically widened to accommodate heavy vehicle traffic or a growing population. While self-assembling road bridges may be a ways off, the example illustrates the potential that technologies built with the same self-assembling capabilities seen in E. hamatum could have.

“There’s a deep interest in creating robots that don’t just rely on themselves, but can exploit the group to do more — and self-assembly is the ultimate in doing more,” Nagpal said. “If you could have small simple robots that were able to navigate complex spaces, but could self-assemble into larger structures — bridges, towers, pulling chains, rafts — when they face something they individually did not have the ability to do, that’s a huge increase in power in what robots would be capable of.”

The spaces E. hamatum bridges are not dramatic by human standards — small rifts in the leaf cover, or between the ends of two sticks. Bridges will be the length of 10 to 20 ants, which is only a few centimeters, Lutz said. That said, E. hamatum swarms form several bridges during the course of a day, which can see the back-and-forth of thousands of ants.

“The bridges are something that happen numerous times every day. They’re creating bridges to optimize their traffic flow and maximize their time,” Lutz said.

“When you’re moving hundreds of thousands of ants, creating a little shortcut can save a lot of energy,” he said. “This is such a unique behavior. You have other types of ants forming structures out of their bodies, but it’s not such a huge part of their lives and daily behavior.”

The research also included Scott Powell, an army-ant expert and assistant professor of biology at George Washington University; Albert Kao, a postdoctoral fellow at Harvard who received his doctorate in ecology and evolutionary biology from Princeton in 2015; and Simon Garnier, an assistant professor of biological sciences at NJIT who studies swarm intelligence and was once a postdoctoral researcher in Couzin’s lab at Princeton.

To conduct their field experiments, Lutz and Reid constructed a 1.5-foot-tall apparatus with ramps on both sides and adjustable arms in the center with which they could adjust the size of the gap. They then inserted the apparatus into active E. hamatum raiding trails that they found in the forests of Barro Colorado Island, Panama. Because ants follow one another’s chemical scent, Lutz and Reid used sticks and leaves from the ants’ trail to get them to reform their column across the device.

Lutz and Reid observed how the ants formed bridges across gaps that were set at angles of 12, 20, 40 and 60 degrees. They gauged how much travel-distance the ants saved with their bridge versus the surface area (in centimeters squared) of the bridge itself. Twelve-degree angles shaved off the most distance (around 11 centimeters) while taking up the fewest workers. Sixty-degree angles had the highest cost-to-benefit ratio. Interestingly, the ants were willing to expend members for 20-degree angles, forming bridges up to 8 centimeters squared to decrease their travel time by almost 12 centimeters, indicating that the loss in manpower was worth the distance saved.

Lutz said that future research based on this work might compare these findings to the living bridges of another army ant species, E. burchellii, to determine if the same principles are in action.

The paper, “Army ants dynamically adjust living bridges in response to a cost-benefit trade-off,” was published Nov. 23 by Proceedings of the National Academy of Sciences. The work was supported by the National Science Foundation (grant nos. PHY-0848755, IOS0-1355061 and EAGER IOS-1251585); the Army Research Office (grant nos. W911NG-11-1-0385 and W911NF-14-1-0431); and the Human Frontier Science Program (grant no. RGP0065/2012).


Journal Reference:

  1. Chris R. Reid, Matthew J. Lutz, Scott Powell, Albert B. Kao, Iain D. Couzin, Simon Garnier. Army ants dynamically adjust living bridges in response to a cost–benefit trade-offProceedings of the National Academy of Sciences, 2015; 201512241 DOI: 10.1073/pnas.1512241112

New evidence of cultural diversification between neighboring chimpanzee communities (University of Cambridge)

22-JUL-2015

VIDEO: CHIMPANZEES USE TOOLS TO FEED ON ARMY ANTS. CREDIT: KATHELIJNE KOOPS

For centuries it has been thought that culture is what distinguishes humans from other animals, but over the past decade this idea has been repeatedly called into question. Cultural variation has been identified in a growing number of species in recent years, ranging from primates to cetaceans. Chimpanzees, our closest living relatives, show the most diverse cultures aside from humans, most notably, in their use of a wide variety of tools.

The method traditionally used to establish the presence of culture in wild animals compares behavioural variation across populations and excludes all behavioural patterns that can be explained by genetic or environmental differences across sites. Nevertheless, it is impossible to conclusively rule out the influence of genetics and environmental conditions in geographically distant populations.

To circumnavigate this problem, researchers, led by Dr. Kathelijne Koops, took a new approach. “We compared neighbouring chimpanzee groups living under similar environmental conditions, which allows for the investigation of fine scale cultural differences, whilst keeping genetics constant,” said Koops.

She and colleagues from Kyoto University and Freie Universität Berlin compared the length of tools used for ‘ant-dipping’ between two neighbouring chimpanzee communities, M-group and S-group, in the Kalinzu Forest, Uganda. Dipping for army ants is one of the hallmark examples of culture in chimpanzees and involves the use of a stick to extract the highly aggressive army ants from their underground nests.

Previous research has shown that ant-dipping tool length varied across chimpanzee study sites in relation to the army ant species (Dorylus spp.) that were present. So Koops compared the availability of the different species of army ants and the length of dipping tools used in the two adjacent chimpanzee communities.

The researchers found that M-group tools were significantly longer than S-group tools, despite identical army ant species availability. Considering the lack of ecological differences between the two communities, the tool length difference was concluded to be cultural. “Our findings highlight how cultural knowledge can generate small-scale cultural diversification in neighbouring groups,” said Koops.

“Given the close evolutionary relationship between chimpanzees and humans, insights into what drives cultural diversification in our closest living relatives will in turn shed light on how cultural differences emerge and are maintained between adjacent groups in human societies,” said Koops, who conducted the work at Cambridge University’s Division of Biological Anthropology and at Zurich University’s Anthropological Institute and Museum.

The research is published today in the Nature journal Scientific Reports.

Chimpanzés caçadores dão pistas sobre os primeiros humanos (El País)

Primatas que usam lanças podem fornecer indícios sobre origem das sociedades humanas

 12 MAY 2015 – 18:14 BRT

Um velho chimpanzé bebe água em um lago, em Fongoli, no Senegal. / FRANS LANTING

Na quente savana senegalesa se encontra o único grupo de chimpanzés que usa lanças para caçar animais com os quais se alimenta. Um ou outro grupo de chimpanzés foi visto portando ferramentas para a captura de pequenos mamíferos, mas esses, na comunidade de Fongoli, caçam regularmente usando ramos afiados. Esse modo de conseguir alimento é um uso cultural consolidado para esse grupo de chimpanzés.

Além dessa inovação tecnológica, em Fongoli ocorre também uma novidade social que os distingue dos demais chimpanzés estudados na África: há mais tolerância, maior paridade dos sexos na caça e os machos mais corpulentos não passam com tanta frequência por cima dos interesses dos demais, valendo-se de sua força. Para os pesquisadores que vêm observando esse comportamento há uma década esses usos poderiam, além disso, oferecer pistas sobre a evolução dos ancestrais humanos.

“São a única população não humana conhecida que caça vertebrados com ferramentas de forma sistemática, por isso constituem uma fonte importante para a hipótese sobre o comportamento dos primeiros hominídeos, com base na analogia”, explicam os pesquisadores do estudo no qual formularam suas conclusões depois de dez anos observando as caçadas de Fongoli. Esse grupo, liderado pela antropóloga Jill Pruetz, considera que esses animais são um bom exemplo do que pode ser a origem dos primeiros primatas eretos sobre duas patas.

Os machos mais fortes dessa comunidade respeitam as fêmeas na caça

Na sociedade Fongoli as fêmeas realizam exatamente a metade das caçadas com lança. Graças à inovação tecnológica que representa a conversão de galhos em pequenas lanças com as quais se ajudam para caçar galagos – pequenos macacos muito comuns nesse entorno –, as fêmeas conseguem certa independência alimentar. Na comunidade de Gombe, que durante muitos anos foi estudada por Jane Goodall, os machos arcam com cerca de 90% do total das presas; em Fongoli, somente 70%. Além disso, em outros grupos de chimpanzés os machos mais fortes roubam uma de cada quatro presas caçadas pelas fêmeas (sem ferramentas): em Fongoli, apenas 5%.

Uma fêmea de chimpanzé apanha e examina um galho que usará para capturar sua presa. / J. PRUETZ

“Em Fongoli, quando uma fêmea ou um macho de baixo escalão captura uma presa, permitem que ele fique com ela e a coma. Em outros lugares, o macho alfa ou outro macho dominante costuma tomar-lhe a presa. Assim, as fêmeas obtêm pouco benefício da caça, se outro chimpanzé lhe tira sua presa”, afirma Pruetz. Ou seja, o respeito dos machos de Fongoli pelas presas obtidas por suas companheiras serviria de incentivo para que elas se decidam a ir à caça com mais frequência do que as de outras comunidades. Durante esses anos de observação, praticamente todos os chimpanzés do grupo – cerca de 30 indivíduos – caçaram com ferramentas,

O clima seco faz com que os macacos mais acessíveis em Fongoli sejam os pequenos galagos, e não os colobos vermelhos – os preferidos dos chimpanzés em outros lugares da África –, que são maiores e difíceis de capturar por outros que não sejam os machos mais rápidos e corpulentos. Quase todos os episódios de caça com lanças observados (três centenas) se deram nos meses úmidos, nos quais outras fontes de alimento são escassas.

A savana senegalesa, com poucas árvores, é um ecossistema que tem uma importante semelhança com o cenário em que evoluíram os ancestrais humanos. Ao contrário de outras comunidades africanas, os chimpanzés de Fongoli passam a maior parte do tempo no chão, e não entre os galhos. A excepcional forma de caça de Fongoli leva os pesquisadores a sugerir em seu estudo que os primeiros hominídeos provavelmente intensificaram o uso de ferramentas tecnológicas para superar as pressões ambientais, e que eram até mesmo “suficientemente sofisticados a ponto de aperfeiçoar ferramentas de caça”.

“Sabemos que o entorno tem um impacto importante no comportamento dos chimpanzés”, afirma o primatólogo Joseph Call, do Instituto Max Planck. “A distribuição das árvores determina o tipo de caça: onde a vegetação é mais frondosa, a caçada é mais cooperativa em relação a outros entornos nos quais é mais fácil seguir a presa, e eles são mais individualistas”, assinala Call.

No entanto, Call põe em dúvida que essas práticas de Fongoli possam ser consideradas caçadas com lança propriamente ditas, já que para ele lembram mais a captura de formigas e cupins usando palitos, algo mais comum entre os primatas. “A definição de caça que os pesquisadores estabelecem em seu estudo não se distingue muito do que fazem colocando um raminho em um orifício para conseguir insetos para comer”, diz Call. Os chimpanzés de Fongoli cutucam com paus os galagos quando eles se escondem em cavidades das árvores para forçá-los a sair e, uma vez fora, lhes arrancam a cabeça com uma mordida. “É algo que fica entre uma coisa e a outra”, argumenta.

Esses antropólogos acreditam que o achado permite pensar que os primeiros hominídeos eretos também usavam lanças

Pruetz responde a esse tipo de crítica dizendo que se trata de uma estratégia para evitar que o macaco os morda ou escape, uma situação muito diferente daquela de colocar um galho em um orifício para capturar bichos. Se for o mesmo, argumentam Pruetz e seus colegas, a pergunta é “por que os chimpanzés de outros grupos não caçam mais”.

Além do caso particular, nem sequer está encerrado o debate sobre se os chimpanzés devem ser considerados modelos do que foram os ancestrais humanos. “Temos de levar em conta que o bonobo não faz nada disso e é tão próximo de nós como o chimpanzé”, defende Call. “Pegamos o chimpanzé por que nos cai bem para assinalar determinadas influências comuns. É preciso ter muito cuidado e não pesquisar a espécie dependendo do que queiramos encontrar”, propõe.

Puppy-Dog Eyes of Science (Savage Minds)

April 24, 2015 – John Hartigan

“Scientists say…” It’s interesting what natural science research starts making the rounds on social media. Mostly on diet or health broadly, and increasingly concerning climate change. On rare occasion—as over the past few days—some reports surface that offer insight into the circulating clutter itself, as in “cute dog” photos. In this instance, they’re opportunities to glimpse changing understandings of big topics, like domestication and evolution.

Links for two articles recently popped up in my Twitter feed: “The Science of Puppy-Dog Eyes” (NYTimes, 4/21/14) and “The Guilty Looking Companion,” Scientific American(4/20/15), both treating the gazing behavior of dogs and its various effects on humans. The first, by Jan Hoffman, reported on a study published in Science (in a themed-column on evolution), titled, “Dogs hijack the human bonding pathway.” The second, by Julie Hecht, “The Guilty Looking Companion,” builds off an article in Behavioral Processes, on a tangled question: “Are owners’ reports of their dogs’ ‘guilty look’ influenced by the dogs’ action and evidence of the misdeed?” Both suggest a far more agential companion species than many people might’ve suspected, but more importantly they each complicate stock domestication narratives suggesting it was something we simply did to them. They also suggest opportunities for extending social analysis beyond the human.

As the title of the Science article suggests, dogs were possibly canny drivers of domestication: “dogs became domesticated in part by adapting to human means of communication: eye contact.” In particular, the speculation is that dogs cleverly “utilized a natural system meant for bonding a parent with his or her child.” Evolutionarily, “the challenge for dogs may simply have been to express a behavioral (and morphological) repertoire that mimicked the cues that elicit caregiving toward our own young. Indeed, these juvenile characteristics of dogs are known to carry a selective advantage with respect to human preferences.” So dogs wile their way into our good graces by coopting the cuteness channel we have for children. To complicate agency a bit further, this seems to all hinge on a bidirectional hormonal mechanism: people and dogs both develop heightened, pleasurable levels of oxytocin from protracted gazing into each other’s eyes. “These findings suggest not only an interspecific effect of oxytocin, but also the exciting possibility of a feedback loop,” since “shifts in oxytocin concentration in a dog might elicit similar changes in a human and vice-versa—just as when a mother bonds with her infant.” Domestication just got a good deal more interesting.

“The guilty looking companion” takes up the theme of sociality and how social bonds are respectively maintained in various species, but also how humans might be duped by our tendency to anthropomorphize dogs as possessing a subjective state approximating shame. The reparative behaviors of appeasement and reconciliation that maintain relationships, practiced by many species, when manifested by dogs, reads easily, to us, as “guilt.” But through a fascinating series of experiments, researchers countered that these canine gestures are just “cohesive displays,” which operate “to reduce conflict, diffuse tension, and reinforce social bonds.” Dogs are not responding to ameliorating a subjective sense of shame at transgressing rules; they are instead “incredibly sensitive to environmental and social cues.” If there’s furniture torn or overturned, the owner is looking for someone to chastise—better grovel or cringe. These behavior are very effective, according to surveys of dog owners, who withhold punishments in the wake of such displays. But Hecht concludes with a caution: “It might just be that we’re anthropomorphizing,” in reference to the viral spew of “dog shamming” photos. “Which, in this case, might not be good for us or our dogs.” Indeed, but what is even more valuable here is the perspective opened up onto thinking about parallel and converging forms of species sociality, beyond the question of who is domesticating who.

On that topic, another recently published science article pursues just these openings, though unfortunately it does not seem to be circulating widely at all. “Testing the myth: Tolerant dogs and aggressive wolves,” in Proceedings B (Royal Society Publishing) reports on findings that indicate “a steeper dominance hierarchy in dogs than in wolves.” While “tolerance” is supposed to be the character trait “selected for,” dogs appear far more aggressive and uncooperative with conspecifics than wolves. The problem with “all domestication theories” to date is that they’ve ignored “apparently contradictory behaviours…observed in dogs and wolf packs.” There’s an enormous amount to this piece, but it may come down to “face,” as Erving Goffman developed the concept. “Visual communication in dogs is somewhat impaired due to their reduced visual (facial as well as bodily) expressions,” which “might lead to an inability to control conflicts in close quarters.” Wolves are far more articulate in reading both gaze and facial features in conspecific communications. Range et al write, “Although dogs and wolves seem to use the same signals overall, it is possible that dogs do not use them as appropriately as wolves”—i.e., they haven’t refined the etiquette of conspecific communications quite as well, though they’re very good at circumventing our conspecific gaze signaling tendencies.

But that “wolves appear tolerant, attentive, and at the same time cooperative towards pack members” is in stark “contrast to the starting point of several recent domestication hypotheses.” Free-ranging dogs—constituting about 76-83% of the global dog population!!—not so much. So the questions swirl as to dogs’ cognitive and emotional processes underlying their intraspecific sociality and how that variously aligns with ours, in the deep past and today.

Galinhas enxergam as cores bem melhor do que os humanos (Folha de S.Paulo)

RICARDO MIOTO

EDITOR DE “CIÊNCIA” E “SAÚDE”

30/03/2015  02h00

Galinhas são animais de visão, diz a ciência. Perto delas, somos uns daltônicos.

Cientistas descobriram que suas retinas têm cinco cones sensíveis à cor. Humanos têm só três, que enxergam comprimentos de vermelho, azul e verde –o resto é mistura. Galinhas nos superam com um cone para violeta e alguns comprimentos ultravioleta e com um quinto receptor, ainda pouco compreendido.

Tatiane Rosa/Folhapress
Galinha da Faculdade de Medicina Veterinária e Zootecnia da USP, no campus de Pirassununga
Galinha da Faculdade de Medicina Veterinária e Zootecnia da USP, no campus de Pirassununga

Além disso, no ano passado cientistas de Princeton (EUA) mostraram que os átomos do olho da galinha se organizam num estado da matéria inédito na biologia, com propriedades tanto de cristal sólido quanto de líquido. Tal arranjo permite que cores sejam recebidas de forma muito nítida.

Foi assim que o olho da galinha foi parar na revista científica “Physical Review”, entre artigos sobre temas da física como dissipação de energia ou mecânica quântica.

Isso tudo faz com que seja difícil imaginarmos como uma galinha vê cores –só sabemos que é bem mais intenso e, digamos, psicodélico.

Por que a evolução deixou o olho da galinha assim? É uma boa pergunta. As respostas passam pela importância das cores para ela –pense, por exemplo, na plumagem colorida dos parceiros sexuais.

Chimps joining new troop learn its ‘words’: study (Reuters)

BY SHARON BEGLEY

NEW YORK, Thu Feb 5, 2015 1:03pm EST

(Reuters) – Just as Bostonians moving to Tokyo ditch “grapefruit” and adopt “pamplemousse,” so chimps joining a new troop change their calls to match those of their new troop, scientists reported on Thursday in the journal Current Biology.

The discovery represents the first evidence that animals besides humans can replace the vocal sounds their native group uses for specific objects – in the chimps’ case, apples – with those of their new community.

One expert on chimp vocalizations, Bill Hopkins of Yerkes National Primate Research Center in Atlanta, who was not involved in the study, questioned some of its methodology, such as how the scientists elicited and recorded the chimps’ calls, but called it “interesting work.”

Chimps have specific grunts, barks, hoots and other vocalizations for particular foods, for predators and for requests such as “look at me,” which members of their troop understand.

Earlier studies had shown that these primates, humans’ closest living relatives, can learn totally new calls in research settings through intensive training. And a 2012 study led by Yerkes’ Hopkins showed that young chimps are able to pick up sounds meaning “human, pay attention to me,” from their mothers.

But no previous research had shown that chimps can replace a call they had used for years with one used by another troop. Instead, primatologists had thought that sounds referring to objects in the environment were learned at a young age and essentially permanent, with any variations reflecting nuances such as how excited the animal is about, say, a banana.

In the new research, scientists studied adult chimpanzees that in 2010 had been moved from a safari park in the Netherlands to Scotland’s Edinburgh Zoo, to live with nine other adults in a huge new enclosure.

It took three years, and the formation of strong social bonds among the animals, but the grunt that the seven Dutch chimps used for “apple” (a favorite food) changed from a high-pitched eow-eow-eow to the lower-pitched udh-udh-udh used by the six Scots, said co-author Simon Townsend of the University of Zurich. The change was apparent even to non-chimp-speakers (scientists).

“We showed that, through social learning, the chimps could change their vocalizations,” Townsend said in an interview. That suggests human language isn’t unique in using socially-learned sounds to signify objects.

Unanswered is what motivated the Dutch chimps to sound more like the Scots: to be better understood, or to fit in by adopting the reining patois?

(Reporting by Sharon Begley; Editing by Nick Zieminski)

Humans, baboons share cumulative culture ability (Science Daily)

Date: November 5, 2014

Source: Le Centre national de la recherche scientifique (CNRS)

Summary: The ability to build up knowledge over generations, called cumulative culture, has given humankind language and technology. While it was thought to be limited to humans until now, researchers have recently found that baboons are also capable of cumulative culture.

Baboon using a touch screen. Credit: © 2014 Nicolas Claidière

The ability to build up knowledge over generations, called cumulative culture, has given mankind language and technology. While it was thought to be limited to humans until now, researchers from the Laboratoire de psychologie cognitive (CNRS/AMU), working in collaboration with colleagues at the University of Edinburgh (UK), have recently found that baboons are also capable of cumulative culture. Their findings are published in Proceedings of the Royal Society B on 5 November 2014.

Humankind is capable of great accomplishments, such as sending probes into space and eradicating diseases; these achievements have been made possible because humans learn from their elders and enrich this knowledge over generations. It was previously thought that this cumulative aspect of culture — whereby small changes build up, are transmitted, used and enriched by others — was limited to humans, but it has now been observed in another primate, the baboon.

While it is clear that monkeys like chimpanzees learn many things from their peers, each individual seems to start learning from scratch. In contrast, humans use techniques that evolve and improve from one generation to the next, and also differ from one population to another. The origin of cumulative culture in humans has therefore remained a mystery to scientists, who are trying to identify the necessary conditions for this cultural accumulation.

Nicolas Claidière and Joël Fagot, of the Laboratoire de psychologie cognitive, conducted the present study at the CNRS Primatology Center in Rousset, southeastern France. Baboons live in groups there and have free access to an area with touch screens where they can play a “memory game” specifically designed for the study. The screen briefly displays a grid of 16 squares, four of which are red and the others white. This image is then replaced by a similar grid, but composed of only white squares, and the baboons must touch the four squares that were previously red. Phase one of the experiment started with a task-learning period in which the position of the four red squares was randomized. Phase two comprised a kind of visual form of “Chinese whispers” wherein information was transmitted from one individual to another. In this second phase, a baboon’s response (the squares touched on the screen) was used to generate the next grid pattern that the following baboon had to memorize and reproduce, and so on for 12 “generations.”

The researchers, in collaboration with Simon Kirby and Kenny Smith from the University of Edinburgh, noted that baboons performed better in the phase involving a transmission chain (compared with random testing, which continued throughout the period of the experiment): success rate (1) increased from 80% to over 95%. Due to errors by the baboons, the patterns evolved between the beginning and the end of each chain. Yet to the surprise of researchers, the random computer-generated patterns were gradually replaced by “tetrominos” (Tetris®-like shapes composed of four adjacent squares), even though these forms represent only 6.2% of possible configurations! An even more surprising result was that the baboons’ performance on these rare shapes was poor during random testing, but increased throughout the transmission chain, during which the tetrominos accumulated. Moreover, when the experiment was replicated several times, the starting patterns did not lead to the same set of tetrominos. This study shows that, like humans, baboons have the ability to transmit and accumulate changes over “cultural generations” and that these incremental changes, which may differ depending on the chain, become structured and more efficient.

Researchers have ensured that all the necessary conditions were present to observe a type of cumulative cultural evolution in non-human primates, with its three characteristic properties (progressive increase in performance, emergence of systematic structures, and lineage specificity). These results show that cumulative culture does not require specifically human capacities, such as language. So why have no examples of this type of cultural evolution been clearly identified in the wild? Perhaps because the utilitarian dimension of non-human primate culture (e.g., the development of tools) hinders such evolution.

(1) The task was considered successful if at least 3 out of 4 squares were correctly memorized.


Journal Reference:

  1. N. Claidière, K. Smith, S. Kirby, J. Fagot. Cultural evolution of systematically structured behaviour in a non-human primate. Proceedings of the Royal Society B, November 2014 DOI: 10.1098/rspb.2014.1541

Chimpanzees have favorite ‘tool set’ for hunting staple food of army ants (University of Cambridge)

15-Oct-2014

Fred Lewsey

This video shows a chimpanzee who has constructed a tool with which to investigate a camera (Nimba mountains, Guinea). 

West African chimpanzees will search far and wide to find Alchornea hirtella, a spindly shrub whose straight shoots provide the ideal tools to hunt aggressive army ants in an ingenious fashion, new research shows.

The plant provides the animals with two different types of tool, a thicker shoot for ‘digging’ and a more slender tool for ‘dipping’.

On locating an army ant colony, chimpanzees will dig into the nest with the first tool – aggravating the insects. They then dip the second tool into the nest, causing the angry ants to swarm up it. Once the slender shoot is covered in ants, the chimpanzees pull it out and wipe their fingers along it: scooping up the ants until they have a substantial handful that goes straight into the mouth in one deft motion.

This technique – ‘ant dipping’ – was previously believed to be a last resort for the hungry apes, only exploited when the animal’s preferred food of fruit couldn’t be found. But the latest study, based on over ten years of data, shows that, in fact, army ants are a staple in the chimpanzee diet – eaten all year round regardless of available sources of fruit. Ants may be an important source of essential nutrients not available in the typical diet, say researchers, as well as a potential source of protein and fats.

The new research, published today in the American Journal of Primatology, was led by Dr Kathelijne Koops from the University of Cambridge’s Division of Biological Anthropology and Junior Research Fellow of Homerton College.

This video shows a male chimpanzee looking on at a female who is using an ant-dipping tool (Kalinzu Forest, Uganda).

“Ant dipping is a remarkable feat of problem-solving on the part of chimpanzees,” said Koops. “If they tried to gather ants from the ground with their hands, they would end up horribly bitten with very little to show for it. But by using a tool set, preying on these social insects may prove as nutritionally lucrative as hunting a small mammal – a solid chunk of protein.”

Koops points out that if Alchornea hirtella is nowhere to be found, chimps will fashion tools from other plants – but seemingly only after an exhaustive search for their preferred tool provider.

Previous research has shown that chimpanzees will actually select longer tools for faster, more aggressive types of army ants. The average ‘dipping’ tool length across the study was 64 centimetres, but dipping tools got up to 76 cm.

The question for Koops is one of animal culture: how do chimpanzees acquire knowledge of such sophisticated techniques?

“Scientists have been working on ruling out simple environmental and genetic explanations for group differences in behaviours, such as tool use, and the evidence is pointing strongly towards it being cultural,” said Koops. “They probably learn tool use behaviours from their mother and others in the group when they are young.”

The research for the ant-dipping study – which took place in Guinea’s Nimba mountains – proved challenging, as the chimpanzees were not habituated to people – so the team acted almost as archaeologists, studying ‘exploited’ ants nests to measure abandoned tool sets and “sifting through faeces for ants heads”.

IMAGE: This image shows a chimpanzee using an ant-dipping tool.

To further study these illusive creatures, Koops set up cameras to take extensive video footage of the chimpanzees and their tool use. In doing so, she managed to capture a chimpanzee who has constructed a tool with which to investigate the camera itself – prodding it curiously and then sniffing the end of the tool (VIDEO 1).

“This study is part of a big ongoing research project. The next stages will involve looking at social opportunities to learn: how much time do youngsters spend within arm’s length of other individuals; how much time do they spend close to their mother; as well as innate predispositions to explore and engage with objects,” said Koops.

A video clip from the Kalinzu Forest in Uganda, where Koops is currently conducting comparative studies on East African chimpanzees, captures a male chimpanzee seemingly looking on enviously at a female who has managed to construct a much better dipping tool than his own and is feasting heartily as a consequence (VIDEO 2). Koops suggests this kind of observing of other individuals may lead to learning within a chimpanzee community.

“By studying our closest living relatives we gain a window into the evolutionary past which allows us to shed light on the origins of human technology and material culture,” added Koops.

A link to the paper can be found here: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1098-2345/earlyview

Crocodiles are sophisticated hunters: Work as a team to hunt their prey (Science Daily)

Date: October 13, 2014

Source: University of Tennessee

Summary: Recent studies have found that crocodiles and their relatives are highly intelligent animals capable of sophisticated behavior such as advanced parental care, complex communication and use of tools for hunting. New research shows just how sophisticated their hunting techniques can be.

Crocodiles (stock image). Credit: © aarstudio / Fotolia

Recent studies have found that crocodiles and their relatives are highly intelligent animals capable of sophisticated behavior such as advanced parental care, complex communication and use of tools for hunting.

New University of Tennessee, Knoxville, research published in the journal Ethology Ecology and Evolution shows just how sophisticated their hunting techniques can be.

Vladimir Dinets, a research assistant professor in UT’s Department of Psychology, has found that crocodiles work as a team to hunt their prey. His research tapped into the power of social media to document such behavior.

Studying predatory behavior by crocodiles and their relatives such as alligators and caimans in the wild is notoriously difficult because they are ambush hunters, have slow metabolisms and eat much less frequently than warm-blooded animals. In addition, they are mostly nocturnal and often hunt in murky, overgrown waters of remote tropical rivers and swamps. Accidental observations of their hunting behavior are often made by non-specialists and remain unpublished or appear in obscure journals.

To overcome these difficulties, Dinets used Facebook and other social media sites to solicit eyewitness accounts from amateur naturalists, crocodile researchers and nonscientists working with crocodiles. He also looked through diaries of scientists and conducted more than 3,000 hours of observations himself.

All that work produced just a handful of observations, some dating back to the 19th century. Still, the observations had something in common — coordination and collaboration among the crocodiles in hunting their prey.

“Despite having been made independently by different people on different continents, these records showed striking similarities. This suggests that the observed phenomena are real, rather than just tall tales or misinterpretation,” said Dinets.

Crocodiles and alligators were observed conducting highly organized game drives. For example, crocodiles would swim in a circle around a shoal of fish, gradually making the circle tighter until the fish were forced into a tight “bait ball.” Then the crocodiles would take turns cutting across the center of the circle, snatching the fish.

Sometimes animals of different size would take up different roles. Larger alligators would drive a fish from the deeper part of a lake into the shallows, where smaller, more agile alligators would block its escape. In one case, a huge saltwater crocodile scared a pig into running off a trail and into a lagoon where two smaller crocodiles were waiting in ambush — the circumstances suggested that the three crocodiles had anticipated each other’s positions and actions without being able to see each other.

“All these observations indicate that crocodilians might belong to a very select club of hunters — just 20 or so species of animals, including humans — capable of coordinating their actions in sophisticated ways and assuming different roles according to each individual’s abilities. In fact, they might be second only to humans in their hunting prowess,” said Dinets.

Dinets said more observations are needed to better understand what exactly the animals are capable of. “And these observations don’t come easily,” he said.

Previous research by Dinets discovered that crocodiles are able to climb trees and use lures such as sticks to hunt prey. More of his crocodile research can be found in his book “Dragon Songs.”


Journal Reference:

  1. Vladimir Dinets. Apparent coordination and collaboration in cooperatively hunting crocodilians. Ethology Ecology & Evolution, 2014; 1 DOI:10.1080/03949370.2014.915432

Killer whales learn to communicate like dolphins (Science Daily)

Date: October 7, 2014

Source: Acoustical Society of America (ASA)

Summary: The sounds that most animals use to communicate are innate, not learned. However, a few species, including humans, can imitate new sounds and use them in appropriate social contexts. This ability, known as vocal learning, is one of the underpinnings of language. Now, researchers have found that killer whales can engage in cross-species vocal learning: when socialized with bottlenose dolphins, they shifted the sounds they made to more closely match their social partners.

Killer whales (Orcinus orca) can engage in cross-species vocal learning: when socialized with bottlenose dolphins, they shifted the types of sounds they made to more closely match their social partners. Credit: © RKP / Fotolia

From barks to gobbles, the sounds that most animals use to communicate are innate, not learned. However, a few species, including humans, can imitate new sounds and use them in appropriate social contexts. This ability, known as vocal learning, is one of the underpinnings of language.

Vocal learning has also been observed in bats, some birds, and cetaceans, a group that includes whales and dolphins. But while avian researchers have characterized vocal learning in songbirds down to specific neural pathways, studying the trait in large marine animals has presented more of a challenge.

Now, University of San Diego graduate student Whitney Musser and Hubbs-SeaWorld Research Institute senior research scientist Dr. Ann Bowles have found that killer whales (Orcinus orca) can engage in cross-species vocal learning: when socialized with bottlenose dolphins, they shifted the types of sounds they made to more closely match their social partners. The results, published in The Journal of the Acoustical Society of America, suggest that vocal imitation may facilitate social interactions in cetaceans.

Killer whales have complex vocal repertoires made up of clicks, whistles and pulsed calls — repeated brief bursts of sound punctuated with silence. The acoustic features of these vocalizations, such as their duration, pitch and pulse pattern, vary across social groups. Whales that are closely related or live together produce similar pulsed calls that carry vocal characteristics distinct to the group, known as a dialect.

“There’s been an idea for a long time that killer whales learn their dialect, but it isn’t enough to say they all have different dialects so therefore they learn. There needs to be some experimental proof so you can say how well they learn and what context promotes learning,” said Bowles.

Testing vocal learning ability in social mammals usually requires observing the animal in a novel social situation, one that might stimulate them to communicate in new ways. Bottlenose dolphins provide a useful comparison species in this respect: they make generally similar sounds but produce them in different proportions, relying more on clicks and whistles than the pulsed calls that dominate killer whale communication.

“We had a perfect opportunity because historically, some killer whales have been held with bottlenose dolphins,” said Bowles. By comparing old recordings of vocalization patterns from the cross-socialized subjects with recordings of killer whales and bottlenose dolphins housed in same-species groups, Bowles and her team were able to evaluate the degree to which killer whales learned vocalization patterns from their cross-species social partners.

All three killer whales that had been housed with dolphins for several years shifted the proportions of different call types in their repertoire to more closely match the distribution found in dolphins — they produced more clicks and whistles and fewer pulsed calls. The researchers also found evidence that killer whales can learn completely new sounds: one killer whale that was living with dolphins at the time of the experiment learned to produce a chirp sequence that human caretakers had taught to her dolphin pool-mates before she was introduced to them.

Vocal learning skills alone don’t necessarily mean that killer whales have language in the same way that humans do. However, they do indicate a high level of neural plasticity, the ability to change circuits in the brain to incorporate new information. “Killer whales seem to be really motivated to match the features of their social partners,” said Bowles, though the adaptive significance of the behavior is not yet known.

There are immediate reasons to study the vocal patterns of cetaceans: these marine mammals are threatened by human activities through competition for fishery resources, entanglement in fishing gear, collisions with vessels, exposure to pollutants and oil spills and, ultimately, shrinking habitats due to anthropogenic climate change. If their social bonds are closely linked to their vocalizations, killer whales’ ability to survive amidst shifting territories and social groups may be tied to their ability to adapt their communication strategies.

“It’s important to understand how they acquire [their vocalization patterns], and lifelong, to what degree they can change it, because there are a number of different [cetacean] populations on the decline right now,” said Bowles. “And where killer whales go, we can expect other small whale species to go — it’s a broader question.”


Journal Reference:

  1. Whitney B. Musser, Ann E. Bowles, Dawn M. Grebner, and Jessica L. Crance.Differences in acoustic features of vocalizations produced by killer whales cross-socialized with bottlenose dolphins. The Journal of the Acoustical Society of America, 2014 DOI: 10.1121/1.4893906

Chimp social network shows how new ideas catch on (New Scientist)

19:00 30 September 2014 by Catherine Brahic

Three years ago, an adult chimpanzee called Nick dipped a piece of moss into a watering hole in Uganda’s Budongo Forest. Watched by a female, Nambi, he lifted the moss to his mouth and squeezed the water out. Nambi copied him and, over the next six days, moss sponging began to spread through the community. A chimp trend was born.

Until that day in November 2011, chimps had only been seen to copy actions in controlled experimentsMovie Camera, and social learning had never been directly observed in the wild.

To prove that Nambi and the seven other chimps who started using moss sponges didn’t just come up with the idea independently, Catherine Hobaiter of the University of St Andrews, UK, and her colleagues used their own innovation: a statistical analysis of the community’s social network. They were able to track how moss-sponging spread and calculated that once a chimp had seen another use a moss sponge, it was 15 times more likely to do so itself.

A decade ago it was believed that only humans have the capacity to imitate, says Frans de Waal of Emory University in Atlanta, Georgia. “The present study is the first on apes to show by means of networking analysis that habits travel along paths of close relationships,” he says, adding that a similar idea was shown not long ago for humpback whale hunting techniques.

Caught in the act

Copying may seem like the easiest thing to us, but not all animals are able. Chimps at the Gombe Stream reserve in Tanzania can copy each other using twigs to fish out termites, but the baboons that watch them haven’t picked up the trick. “They don’t get it,” says Andrew Whiten of the University of St Andrews.

Whiten previously listed 39 behaviours that were found only in some communities of chimps, suggesting these were picked up from other group members rather than being innate behaviours. Since then, more have been added, but they still number in the dozens, not the thousands.

Given how rarely chimps pick up trends, it’s exciting that someone was on hand to watch it happen in this latest study, says Whiten.

Ultimately, he says, our ability to both invent and copy meant our ancestors could exploit a cognitive niche. “They began hunting large game by doing it the brainy way.” Imitation, it turns out, is not just the sincerest form of flattery, it’s also a smart thing to do.

Journal reference: PLoS Biology, DOI: 10.1371/journal.pbio.1001960

Dolphins are attracted to magnets: Add dolphins to the list of magnetosensitive animals, French researchers say (Science Daily)

Date: September 29, 2014

Source: Springer Science+Business Media

Summary: Add dolphins to the list of magnetosensitive animals, French researchers say. Dolphins are indeed sensitive to magnetic stimuli, as they behave differently when swimming near magnetized objects.

Bottlenose dolphins (stock image). Credit: © sanilda / Fotolia

Add dolphins to the list of magnetosensitive animals, French researchers say. Dolphins are indeed sensitive to magnetic stimuli, as they behave differently when swimming near magnetized objects. So says Dorothee Kremers and her colleagues at Ethos unit of the Université de Rennes in France, in a study in Springer’s journalNaturwissenschaften — The Science of Nature. Their research, conducted in the delphinarium of Planète Sauvage in France, provides experimental behavioral proof that these marine animals are magnetoreceptive.

Magnetoreception implies the ability to perceive a magnetic field. It is supposed to play an important role in how some land and aquatic species orientate and navigate themselves. Some observations of the migration routes of free-ranging cetaceans, such as whales, dolphins and porpoises, and their stranding sites suggested that they may also be sensitive to geomagnetic fields.

Because experimental evidence in this regard has been lacking, Kremers and her colleagues set out to study the behavior of six bottlenose dolphins in the delphinarium of Planète Sauvage in Port-Saint-Père. This outdoor facility consists of four pools, covering 2,000 m² of water surface. They watched the animals’ spontaneous reaction to a barrel containing a strongly magnetized block or a demagnetized one. Except from this characteristic, the blocks were identical in form and density. The barrels were therefore indistinguishable as far as echolocation was concerned, the method by which dolphins locate objects by bouncing sound waves off them.

During the experimental sessions, the animals were free to swim in and out of the pool where the barrel was installed. All six dolphins were studied simultaneously, while all group members were free to interact at any time with the barrel during a given session. The person who was assigned the job to place the barrels in the pools did not know whether it was magnetized or not. This was also true for the person who analyzed the videos showing how the various dolphins reacted to the barrels.

The analyses of Ethos team revealed that the dolphins approached the barrel much faster when it contained a strongly magnetized block than when it contained a similar not magnetized one. However, the dolphins did not interact with both types of barrels differently. They may therefore have been more intrigued than physically drawn to the barrel with the magnetized block.

“Dolphins are able to discriminate between objects based on their magnetic properties, which is a prerequisite for magnetoreception-based navigation,” says Kremers. “Our results provide new, experimentally obtained evidence that cetaceans have a magenetic sense, and should therefore be added to the list of magnetosensitive species.”

Journal Reference:

  1. Dorothee Kremers, Juliana López Marulanda, Martine Hausberger, Alban Lemasson. Behavioural evidence of magnetoreception in dolphins: detection of experimental magnetic fields. Naturwissenschaften, 2014 DOI:10.1007/s00114-014-1231-x

Dogs can be pessimists, too (Science Daily)

Date: September 18, 2014

Source: University of Sydney

Summary: Dogs generally seem to be cheerful, happy-go-lucky characters, so you might expect that most would have an optimistic outlook on life. In fact some dogs are distinctly more pessimistic than others, new research shows.

English bulldog puppies. Some dogs are distinctly more pessimistic than others. In fact some dogs are distinctly more pessimistic than others, research from the University of Sydney shows. Credit: © B.Stefanov / Fotolia

Dogs generally seem to be cheerful, happy-go-lucky characters, so you might expect that most would have an optimistic outlook on life.

In fact some dogs are distinctly more pessimistic than others, research from the University of Sydney shows.

“This research is exciting because it measures positive and negative emotional states in dogs objectively and non-invasively. It offers researchers and dog owners an insight into the outlook of dogs and how that changes,” said Dr Melissa Starling, from the Faculty of Veterinary Science. Her PhD research findings are published in PLOS One today.

“Finding out as accurately as possible whether a particular dog is optimistic or pessimistic is particularly helpful in the context of working and service dogs and has important implications for animal welfare.”

Dogs were taught to associate two different sounds (two octaves apart) with whether they would get the preferred reward of milk or instead get the same amount of water. Once the dogs have learnt the discrimination task, they are presented with ‘ambiguous’ tones.

If dogs respond after ambiguous tones, it shows that they expect good things will happen to them, and they are called optimistic. They can show how optimistic they are by which tones they respond to. A very optimistic dog may even respond to tones that sound more like those played before water is offered.

“Of the dogs we tested we found more were optimistic than pessimistic but it is too early to say if that is true of the general dog population,” said Dr Starling.

However it does mean that both individuals and institutions (kennels, dog minders) can have a much more accurate insight into the emotional make-up of their dogs.

According to the research a dog with an optimistic personality expects more good things to happen, and less bad things. She will take risks and gain access to rewards. She is a dog that picks herself up when things don’t go her way, and tries again. Minor setbacks don’t bother her.

If your dog has a pessimistic personality, he expects less good things to happen and more bad things. This may make him cautious and risk averse. He may readily give up when things don’t go his way, because minor setbacks distress him. He may not be unhappy per se, but he is likely to be most content with the status quo and need some encouragement to try new things.

“Pessimistic dogs appeared to be much more stressed by failing a task than optimistic dogs. They would whine and pace and avoid repeating the task while the optimistic dogs would appear unfazed and continue,” said Dr Starling.

“This research could help working dog trainers select dogs best suited to working roles. If we knew how optimistic or pessimistic the best candidates for a working role are, we could test dogs’ optimism early and identify good candidates for training for that role. A pessimistic dog that avoids risks would be better as a guide dog while an optimistic, persistent dog would be more suited to detecting drugs or explosives.”

Dr Starling has been working with Assistance Dogs Australia, a charity organisation that provides service and companion dogs to people with disabilities, to investigate whether an optimism measure could aid in selecting suitable candidates for training.

The research not only suggests how personality may affect the way dogs see the world and how they behave but how positive or negative their current mood is.

“This research has the potential to completely remodel how animal welfare is assessed. If we know how optimistic or pessimistic an animal usually is, it’s possible to track changes in that optimism that will indicate when it is in a more positive or negative emotional state than usual,” said Dr Starling.

“The remarkable power of this is the opportunity to essentially ask a dog ‘How are you feeling?’ and get an answer. It could be used to monitor their welfare in any environment, to assess how effective enrichment activities might be in improving welfare, and pinpoint exactly what a dog finds emotionally distressing.”

Journal Reference:
  1. Melissa J. Starling, Nicholas Branson, Denis Cody, Timothy R. Starling, Paul D. McGreevy. Canine Sense and Sensibility: Tipping Points and Response Latency Variability as an Optimism Index in a Canine Judgement Bias Assessment. PLoS ONE, 2014; 9 (9): e107794 DOI:10.1371/journal.pone.0107794