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.
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.
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.
Date: January 21, 2016
Source: American Association for the Advancement of Science
Summary: A new study reveals that prairie voles console loved ones who are feeling stressed — and it appears that the infamous ‘love hormone,’ oxytocin, is the underlying mechanism.
A new study reveals that prairie voles console loved ones who are feeling stressed — and it appears that the infamous “love hormone,” oxytocin, is the underlying mechanism. Until now, consolation behavior has only been documented in a few nonhuman species with high levels of sociality and cognition, such as elephants, dolphins and dogs.
Prairie voles are particularly social rodents, causing them to be the focus of many studies. This led James Burkett and colleagues to explore their potential for empathy-motivated behaviors.
The researchers created an experiment where relatives and known individuals were temporarily isolated from each other, while one was exposed to mild shocks. Upon reunion, the non-stressed prairie voles proceeded to lick the stressed voles sooner and for longer durations, compared to a control scenario where individuals were separated but neither was exposed to a stressor.
Measurements of hormone levels revealed that the family members and friends were distressed when they could not comfort their loved one.
The fact that consoling behavior occurred only between those who were familiar with each other — including non-kin members — but not strangers, demonstrates that the behavior is not simply a reaction to aversive cues, the authors note.
Since the oxytocin receptor is associated with empathy in humans, Burkett et al. blocked this neurotransmitter in prairie voles in a series of similar consolation experiments. Blocking oxytocin did not cause family members and friends to alter their self-grooming behavior, yet they did cease consoling each other.
These findings provide new insights into the mechanisms of empathy and the evolution of complex empathy-motivated behaviors.
- J. P. Burkett, E. Andari, Z. V. Johnson, D. C. Curry, F. B. M. de Waal, L. J. Young. Oxytocin-dependent consolation behavior in rodents. Science, 2016; 351 (6271): 375 DOI: 10.1126/science.aac4785
OXFORD, England — Before humans milked cows, herded goats or raised hogs, before they invented agriculture, or written language, before they had permanent homes, and most certainly before they had cats, they had dogs.
Or dogs had them, depending on how you view the human-canine arrangement. But scientists are still debating exactly when and where the ancient bond originated. And a large new study being run out of the University of Oxford here, with collaborators around the world, may soon provide some answers.
Scientists have come up with a broad picture of the origins of dogs. First off, researchers agree that they evolved from ancient wolves. Scientists once thought that some visionary hunter-gatherer nabbed a wolf puppy from its den one day and started raising tamer and tamer wolves, taking the first steps on the long road to leashes and flea collars. This is oversimplified, of course, but the essence of the idea is that people actively bred wolves to become dogs just the way they now breed dogs to be tiny or large, or to herd sheep.
The prevailing scientific opinion now, however, is that this origin story does not pass muster. Wolves are hard to tame, even as puppies, and many researchers find it much more plausible that dogs, in effect, invented themselves.
Arden Hulme-Beaman cutting a piece from an ancient skull for DNA testing at the Royal Belgian Institute of Natural Sciences in Brussels. ANDREW TESTA FOR THE NEW YORK TIMES
One reason for the conflicting theories, according to Greger Larson, a biologist in the archaeology department at the University of Oxford, is that dog genetics are a mess. In an interview at his office here in November, he noted that most dog breeds were invented in the 19th century during a period of dog obsession that he called “the giant whirlwind blender of the European crazy Victorian dog-breeding frenzy.”
That blender, as well as random breeding by dogs themselves, and interbreeding with wolves at different times over at least the last 15,000 years, created a “tomato soup” of dog genetics, for which the ingredients are very hard to identify, Dr. Larson said.
The way to find the recipe, Dr. Larson is convinced, is to create a large database of ancient DNA to add to the soup of modern canine genetics. And with a colleague, Keith Dobney at the University of Aberdeen, he has persuaded the Who’s Who of dog researchers to join a broad project, with about $2.5 million in funding from the Natural Environment Research Council in England and the European Research Council, to analyze ancient bones and their DNA.
Robert Wayne, an evolutionary biologist at U.C.L.A. who studies the origin of dogs and is part of the research, said, “There’s hardly a person working in canine genetics that’s not working on that project.”
A wolf on display at the Oxford Museum of Natural History. ANDREW TESTA FOR THE NEW YORK TIMES
That is something of a triumph, given the many competing theories in this field. “Almost every group has a different origination hypothesis,” he said.
But Dr. Larson has sold them all on the simple notion that the more data they have, the more cooperative the effort is, the better the answers are going to be. His personality has been crucial to promoting the team effort, said Dr. Wayne, who described Dr. Larson as “very outgoing, gregarious.” Also, Dr. Wayne added, “He has managed not to alienate anyone.”
Scientists at museums and universities who are part of the project are opening up their collections. So to gather data, Dr. Larson and his team at Oxford have traveled the world, collecting tiny samples of bone and measurements of teeth, jaws and occasionally nearly complete skulls from old and recent dogs, wolves and canids that could fall into either category. The collection phase is almost done, said Dr. Larson, who expects to end up with DNA from about 1,500 samples, and photographs and detailed measurements of several thousand.
Scientific papers will start to emerge this year from the work, some originating in Oxford, and some from other institutions, all the work of many collaborators.
Dr. Larson is gambling that the project will be able to determine whether the domestication process occurred closer to 15,000 or 30,000 years ago, and in what region it took place. That’s not quite the date, GPS location and name of the ancient hunter that some dog lovers might hope for.
But it would be a major achievement in the world of canine science, and a landmark in the analysis of ancient DNA to show evolution, migrations and descent, much as studies of ancient hominid DNA have shown how ancient humans populated the globe and interbred with Neanderthals.
And why care about the domestication of dogs, beyond the obsessive interest so many people have in their pets? The emergence of dogs may have been a watershed.
“Maybe dog domestication on some level kicks off this whole change in the way that humans are involved and responding to and interacting with their environment,” he added. “I don’t think that’s outlandish.”
Shepherding the Research
Dr. Larson is no stranger to widely varying points of view. He is an American, but recently became a British citizen as well. His parents are American and he visited the United States often as a child, but he was born in Bahrain and grew up in Turkey and Japan, places where his parents were teaching in schools on American military bases.
He graduated from Claremont McKenna College in California and received his Ph.D. at Oxford. In between college and graduate studies, he spent a year searching for the bed of an ancient river in Turkmenistan, and another couple of years setting up an environmental consulting office in Azerbaijan. He had an interest in science as an undergraduate, and some background from a college major in environment, economics and politics, but no set career plans. Instead, his career grew out of intense curiosity, a knack for making friends and a willingness to jump at an opportunity, like the time he managed to tag along on an archaeological dig.
He was staying in Ashgabat, Turkmenistan, and a local man who had helped him rent an old Soviet truck to explore the desert told him some Westerners were arriving to go on a dig, so he wangled his way onto one of the trucks.
“I think everybody there thought I was with somebody else,” Dr. Larson said.
By the time the group stopped to rest and someone asked him who he was, it was too late to question whether he really belonged. “I was a complete stowaway,” he said.
But he could move dirt and speak Russian, and he had some recently acquired expertise — in college drinking games — that he said was in great demand at night. By luck, he said, the researchers on the dig turned out to be “the great and the good of British neolithic archaeology.” One of them was Chris Gosden, the chairman of European Archaeology at Oxford, who later invited him to do a one-year master’s degree in archaeology at Oxford. That eventually led to a Ph.D. program after he spent some time in graduate school in the United States.
The current project began when he became fed up with the lack of ancient DNA evidence in papers about the origin of dogs. He called Dr. Dobney, of the University of Aberdeen in 2011, and said, “We’re doing dogs.”
After receiving the grant from the council in England, he and Dr. Dobney organized a conference in Aberdeen, Scotland, to gather as many people involved in researching dog origins as they could. His pitch to the group was that despite their different points of view, everyone was interested in the best possible evidence, no matter where it led.
“If we have to eat crow, we eat crow,” he said. “It’s science.”
A 32,000-Year-Old Skull
Mietje Germonpré, a paleontologist at the Royal Belgian Institute of Natural Sciences, is one of the many scientists participating in the dog project. She was one of a number of authors on a 2013 paper in Science that identified a skull about 32,000 years old from a Belgian cave in Goyet as an early dog. Dr. Wayne at U.C.L.A. was the senior author on the paper and Olaf Thalmann from the University of Turku in Finland was the first author.
It is typical of Dr. Larson’s dog project that although he disagreed with the findings of the paper, arguing that the evidence just wasn’t there to call the Goyet skull a dog, all of the authors of the paper are working on the larger project with him.
In November in Brussels, holding the priceless fossil, Dr. Germonpré pointed out the wide skull, crowded teeth and short snout of the ancient skull — all indicators to her that it was not a wolf.
“To me, it’s a dog,” she said. Studies of mitochondrial DNA, passed down from females only, also indicated the skull was not a wolf, according to the 2013 paper.
Dr. Germonpré said she thinks dogs were domesticated some time before this animal died, and she leans toward the idea that humans intentionally bred them from wolves.
She holds up another piece of evidence, a reconstruction of a 30,000-year-old canid skull found near Predmostí, in the Czech Republic, with a bone in its mouth. She reported in 2014 that this was a dog. And she says the bone is part of evidence the animal was buried with care. “We think it was deliberately put there,” she said.
But she recognizes these claims are controversial and is willing, like the rest of the world of canine science, to risk damage to the fossils themselves to get more information on not just the mitochondrial DNA but also the nuclear DNA.
To minimize that risk, she talked with Ardern Hulme-Beaman, a postdoctoral researcher with the Oxford team, about where to cut into it. He was nearing the end of months of traveling to Russia, Turkey, the United States and all over Europe to take samples of canid jaws and skulls.
He and Allowyn Evin, now with the National Center for Scientific Research in Montpelier, France, also took many photographs of each jaw and skull to do geometric morphometrics. Software processes detailed photographs from every angle into 3-D recreations that provide much more information on the shape of a bone than length and width measurements.
Dr. Germonpré and Dr. Hulme-Beaman agreed on a spot in the interior of the skull to cut. In the laboratory, he used a small electric drill with a cutting blade to remove a chunk the size of a bit of chopped walnut. An acrid, burning smell indicated that organic material was intact within the bone — a good sign for the potential retrieval of DNA.
Back in Oxford, researchers will attempt to use the most current techniques to get as much DNA as possible out of the sample. There is no stretch of code that says “wolf” or “dog,” any more than there is a single skull feature that defines a category. What geneticists try to establish is how different the DNA of one animal is from another. Adding ancient DNA gives many more points of reference over a long time span.
Dr. Larson hopes that he and his collaborators will be able to identify a section of DNA in some ancient wolves that was passed on to more doglike descendants and eventually to modern dogs. And he hopes they will be able to identify changes in the skulls or jaws of those wolves that show shifts to more doglike shapes, helping to narrow the origins of domestication.
The usual assumption about domestic animals is that the process of taming and breeding them happened once. But that’s not necessarily so. Dr. Larson and Dr. Dobney showed that pigs were domesticated twice, once in Anatolia and once in China. The same could be true of dogs.
Only the Beginning
Although the gathering of old bones is almost done, Dr. Larson is still negotiating with Chinese researchers for samples from that part of the world, which he says are necessary. But he hopes they will come.
If all goes well, said Dr. Larson, the project will publish a flagship paper from all of the participants describing their general findings. And over the next couple of years, researchers, all using the common data, will continue to publish separate findings.
Other large collaborative efforts are brewing, as well. Dr. Wayne, at U.C.L.A., said that a group in China was forming with the goal of sequencing 10,000 dog genomes. He and Dr. Larson are part of that group.
Last fall, Dr. Larson was becoming more excited with each new bit of data, but not yet ready to tip his hand about what conclusions the data may warrant, or how significant they will be.
But he is growing increasingly confident that they will find what they want, and come close to settling the thorny question of when and where the tearing power of a wolf jaw first gave way to the persuasive force of a nudge from a dog’s cold nose.
“I’m starting to drink my own Kool-Aid,” he said.
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.
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).
- 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-off. Proceedings of the National Academy of Sciences, 2015; 201512241 DOI: 10.1073/pnas.1512241112
- October 29, 2015
- University of Illinois at Urbana-Champaign
- Even as larvae, honey bees are tuned in to the social culture of the hive, becoming more or less aggressive depending on who raises them, researchers report.
Even as larvae, honey bees are tuned in to the social culture of the hive, becoming more or less aggressive depending on who raises them, researchers report in the journal Scientific Reports.
“We are interested in the general issue of how social information gets under the skin, and we decided to take a chance and ask about very young bees that are weeks away from adulthood,” said University of Illinois entomology professor and Carl R. Woese Institute for Genomic Biology director Gene Robinson, who led the research with postdoctoral researcher Clare Rittschof and Pennsylvania State University professor Christina Grozinger.
“In a previous study, we cross-fostered adult bees from gentle colonies into more aggressive colonies and vice versa, and then we measured their brain gene expression,” Robinson said. “We found that the bees had a complex pattern of gene expression, partly influenced by their own personal genetic identity and partly influenced by the environment of the colony they were living in. This led us to wonder when they become so sensitive to their social environment.”
In the new study, the researchers again cross-fostered bees, but this time as larvae in order to manipulate the bees’ early life experiences. The larvae were from a variety of queens, with sister larvae divided between high- and low-aggression colonies.
The larvae were removed from their foster hives and put into a neutral laboratory environment one day before they emerged as adults. The researchers tested their aggressiveness by exposing them to an intruder bee.
They were surprised to see that the bees retained the social information they had acquired as larvae. Those raised in aggressive colonies were 10 to 15 percent more aggressive than those raised in the gentler colonies.
“Even sisters born of the same queen but reared in different colonies differed in aggression, demonstrating the potency of this environmental effect,” Robinson said.
The finding was surprising in part because bee larvae undergo metamorphosis, which radically changes the structure of their bodies and brains.
“It’s hard to imagine what elements of the brain are influenced during the larval period that then survive the massive reorganization of the brain to bias behavior in this way,” Robinson said.
The aggressive honey bees also had more robust immune responses than their gentler counterparts, the team found.
“We challenged them with pesticides and found that the aggressive bees were more resistant to pesticide,” Grozinger said. “That’s surprising considering what we know from vertebrates, where stress in early life leads to a diminishment of resilience. With the bees, we saw an increase in resilience.”
This finding also suggests that the effects of the social environment on young bees could extend beyond brain function and behavior, Robinson said.
The researchers don’t yet know how the social information is being transmitted to the larvae. They tested whether the bees differed in size, which would suggest that they had been fed differently, but found no size differences between aggressive and gentle bees.
“Adult honey bees are well known for their sociality, their communication skills and their ability to adjust their behavior in response to the needs of the hive,” Rittschof said.
“In mammals, including humans, the effects of early life social interactions often persist throughout adulthood despite additional social experiences,” she said. “A similar pattern in honey bees has broad implications for our understanding of social behavior within the hive and in comparison with other species.”
- Clare C. Rittschof, Chelsey B. Coombs, Maryann Frazier, Christina M. Grozinger, Gene E. Robinson. Early-life experience affects honey bee aggression and resilience to immune challenge. Scientific Reports, 2015; 5: 15572 DOI: 10.1038/srep15572
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.
Primatas que usam lanças podem fornecer indícios sobre origem das sociedades humanas
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.
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%.
“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.
(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)
In just four decades, Ebola has wiped out one third of the world’s chimp and gorilla populations. If it continues, the results will be devastating.
While coverage of the current Ebola epidemic in West Africa remains centered on the human populations in Guinea, Sierra Leone, and Liberia, wildlife experts’ concern is mounting over the virus’ favorite victims: great apes.
Guinea, where the epidemic originated, has the largest population of chimpanzees in all of West Africa. Liberia is close behind. Central Africa is home to western lowland gorillas, the largest and most widespread of all four species. Due to forest density, the number of those infected is unknown. But with hundreds of thousands of ape casualties from Ebola, it’s doubtful they’ve escaped unscathed.
Animal activists are ramping up efforts to find an Ebola vaccine for great apes, but with inadequate international support for human research, their mission could be seen as competing with one to save humans. Experts from the Jane Goodall Institute of Canada insist such apprehension would be misplaced. Two streams of funding—one for humans, one for apes—can coexist in this epidemic, they assert, and must.
“The media was really focusing on human beings,” Sophie Muset, project manager for JGI, says. “But it has been traumatic to [the great ape] population for many years.”
Over the course of just four decades, Ebola has wiped out one third of the world’s population of chimpanzees and gorillas, which now stand at less than 300,000 and 95,000 respectively.
The first large-scale “die-offs” due to Ebola began in the late 1990s, and haven’t stopped. Over the course of just four decades, Ebola has wiped out one third of the world’s population of chimpanzees and gorillas, which now stand at less than 300,000 and 95,000 respectively. Both species are now classified as endangered by the International Union for Conservation of Nature; western gorillas are “critically” so.
One of earliest Ebola “die-offs” of great apes came in 1994, when an Ebola outbreak in Minkébé decimated the region’s entire population—once the second largest in the world. In 2002, an outbreak in the Democratic Republic of Congo wiped out 95 percent of the region’s gorilla population. And an equally brutal attack broke out in 2006, when Ebola Zaire in Gabon (the same strain as the current outbreak) left an estimated 5,000 gorillas dead.
The dwindling population of both species, combined with outside poaching threats, means Ebola poses a very real threat to their existence. To evaluate the damage thus far, the Wild Chimpanzee Foundation is conducting population assessments in West Africa, with the goal of getting a rough estimate of how many have died. Given the combined damage that Ebola has inflicted on this population, the results are likely to be troubling.
In a way, great apes are Ebola’s perfect victims. Acutely tactile mammals, their dynamic social environments revolve around intimacy with each other. Touching hands, scratching backs, hugging, kissing, and tickling, they are near constantly intertwined—giving Ebola a free ride.
In a May 2007 study from The American Naturalist, researchers studying the interactions between chimpanzees and gorillas found evidence the Ebola can even spread between the social groups. At three different sites in northern Republic of Congo, they found bacteria from gorillas and chimps on the same fruit trees. For a virus that spreads through bodily fluids, this is an ideal scenario.
“They live in groups [and] they are very close,” says Muset, who has worked with chimps on the ground in Uganda and the DRC. “Since Ebola transmission happens through body fluids, it spreads very fast.”
For gorillas in particular, this culture proves deadly, making their mortality rate for this virus closer to 95 percent. But like humans, the corpses of chimpanzees and gorillas remain contagious with Ebola for days. While the chimps and gorillas infected with Ebola will likely die in a matter of days, the virus can live on in their corpse for days—in turn, spreading to humans who eat or touch their meat.
It is one such interaction that could result in the spread from apes to humans. But in this particular outbreak, experts have zeroed in on the fruit bat (believed to be the original carrier) as the source. The index patient, a 2-year-old in Guinea, was reportedly playing on a tree with a fruit bat colony.
Whether or not a great ape was involved in the transmission of the virus to humans during this outbreak is unknown. Such an interaction is possible. Interestingly, however, it’s not the risk that great apes with Ebola pose to humans that wildlife experts find most concerning. It’s the risk that their absence poses to the wild.
Owing to a diet consisting mostly of fruit, honey, and leaves, gorillas and chimpanzees are crucial to forest life. Inadvertently distributing seeds and pollen throughout the forest, they stimulate biodiversity within it. Without them, the biodiversity of the vegetation may plummet, endangering all of the species that relied on it—and, in turn, the people that relied on them.
“They are not the only ones who act as seed dispersers,” says Muset. “But they are the big players in that field. So when [a die-off] happens, it can decimate an entire forest.”
Wildlife experts worldwide are working to raise both awareness and funds for a vaccination process. It’s a battle that she says was gaining speed last January, when a researcher announced that he had found a vaccine that could work in chimps But as the epidemic in West Africa grew, the focus shifted.
But Muset says its time to return to the project. “There is a vaccine, but it has never been tested on chimpanzees,” she says. “Progress has been made, and preliminary testing done, but testing in the field need to happen to make it real.”
As to the question of whether it’s ethical to be searching for a vaccine for wild animals when humans are still suffering as well, Muset is honest. “For sure there is a direct competition here. But wildlife and humans have a lot of diseases in common that they can transmit from one to the other,” she says. “And I think you can think of it as two streams of funding, one to wildlife and the other to human beings.”
While it’s great apes that wildlife experts are seeking to save, human nature as a whole, Muset argues, is at stake. “If you want a healthy ecosystem, the more you have to invest in health for wildlife and humans,” she says. “Then, the better place it will be. Because really, it all works together.”
November 26, 2014
When people hear another person talking to them, they respond not only to what is being said — those consonants and vowels strung together into words and sentences — but also to other features of that speech — the emotional tone and the speaker’s gender, for instance. Now, a report provides some of the first evidence of how dogs also differentiate and process those various components of human speech.
The results from this study support the idea that our canine companions are paying attention “not only to who we are and how we say things, but also to what we say,” authors say. Credit: © Uros Petrovic / Fotolia
When people hear another person talking to them, they respond not only to what is being said–those consonants and vowels strung together into words and sentences–but also to other features of that speech–the emotional tone and the speaker’s gender, for instance. Now, a report in the Cell Press journal Current Biology on November 26 provides some of the first evidence of how dogs also differentiate and process those various components of human speech.
“Although we cannot say how much or in what way dogs understand information in speech from our study, we can say that dogs react to both verbal and speaker-related information and that these components appear to be processed in different areas of the dog’s brain,” says Victoria Ratcliffe of the School of Psychology at the University of Sussex.
Previous studies showed that dogs have hemispheric biases–left brain versus right–when they process the vocalization sounds of other dogs. Ratcliffe and her supervisor David Reby say it was a logical next step to investigate whether dogs show similar biases in response to the information transmitted in human speech. They played speech from either side of the dog so that the sounds entered each of their ears at the same time and with the same amplitude.
“The input from each ear is mainly transmitted to the opposite hemisphere of the brain,” Ratcliffe explains. “If one hemisphere is more specialized in processing certain information in the sound, then that information is perceived as coming from the opposite ear.”
If the dog turned to its left, that showed that the information in the sound being played was heard more prominently by the left ear, suggesting that the right hemisphere is more specialized in processing that kind of information.
The researchers did observe general biases in dogs’ responses to particular aspects of human speech. When presented with familiar spoken commands in which the meaningful components of words were made more obvious, dogs showed a left-hemisphere processing bias, as indicated by turning to the right. When the intonation or speaker-related vocal cues were exaggerated instead, dogs showed a significant right-hemisphere bias.
“This is particularly interesting because our results suggest that the processing of speech components in the dog’s brain is divided between the two hemispheres in a way that is actually very similar to the way it is separated in the human brain,” Reby says.
Of course, it doesn’t mean that dogs actually understand everything that we humans might say or that they have a human-like ability of language–far from it. But, says Ratcliffe, these results support the idea that our canine companions are paying attention “not only to who we are and how we say things, but also to what we say.”
All of this should come as good news to many of us dog-loving humans, as we spend considerable time talking to our respective pups already. They might not always understand you, but they really are listening.
- Ratcliffe et al. Orienting asymmetries in dogs’ responses to different communicatory components of human speech. Current Biology, November 2014
11/23/2014 @ 10:31AM By John Farrell
There are books to read from cover to cover in a week or two, and then there are the ones you dip into over and over again, because they aren’t books so much as encyclopedias.
Russell H. Tuttle’s Apes and Human Evolution is one of these. Like the late Stephen Jay Gould’s magisterial Structure of Evolutionary Theory, Tuttle’s tome is a grand synthesis of all the latest research and data about apes and their relation to us.
Tuttle is Professor of Anthropology, Evolutionary Biology, History of Science and Medicine and the College at the University of Chicago.
Tuttle believes that bipedalism preceded the development of the brain in early humans –and was likely something inherited from smaller apes already used to using their feet to move laterally along branches in trees. Although chimpanzees and bonobos are our closest relatives on the evolutionary tree, they do not represent in their own locomotion good proto-models of what led to human upright posture and walking.
While the book does not need to be read in any particular order, the first two chapters set the stage and the terminology for the rest of Apes and Human Evolution, which consists of five parts, totaling 13 dense chapters. A glossary of terms would have helped, but it’s not too much of a distraction to look up the specialist terms Tuttle introduces in these opening sections.
But lest you think it is intended chiefly for colleagues in the fields of anthropology and evolutionary biology, Tuttle’s style throughout is crisp and often witty. (The chapter on the development of human bipedalism, for example, is called ‘How to Achieve an Erection’.)
The opening chapter, ‘Mongrel Models and Seductive Scenarios of Human Evolution’ discusses several hypotheses of human origins, some of which Tuttle argues are biased and which in recent years more detailed study of apes has refuted.
He has a low opinion, for example, of the idea that humans are in essence a species of ‘killer apes’, a notion that gained popularity during the last century. “The views of Charles Darwin,” he writes, “are restrained in comparison with the speculations by the advocates of killer ape scenarios, which flourished for several decades after the horrors of World War I and World War II.”
Darwin portrayed early man (his term) as having “sprung from some comparatively weak creature,” who was not speedy and who lacked natural bodily defenses, namely, formidable canine teeth. Consequently, this bipedal creature was stimulated to use his intellectual powers to make weapons for defense and hunting and to cooperate with “his fellow-men”.
What distinguishes humans among the approximately 400 extant species of primates? In Tuttle’s view, a constellation of morphological and behavioral characteristics, some of which only can be traced precisely through the fossil and archeological records.
Obligate terrestrial bipedalism, precision-gripping hands, reduced teeth and jaws, and ballooned brains can be identified if fossils are complete enough in the skeletal regions under study. Archeological artifacts and features can indicate the presence of tool use and manufacture, control of fire, fabricated shelters, bodily ornamentation, mortuary practice, plastic and graphic arts, and other indications of cognitive skills and culture.
There are also the features that can’t be easily found in fossils or the archeological records, primarily social: cooperation, the ability to enlist new members from outside the immediate community of hominids.
Space does not allow a detailed review of each chapter, summaries of which you can find here. But in the final part, ‘What Makes Us Human?’, Tuttle reveals more of his own philosophical reflections on the matter.
One passage that struck me, for example, occurs in the sub-section, ‘What is More Real: God or Race?’
I believe that God is an ever-increasing collective emergent of the love of all beings past, present and future, but this cannot be proven by available scientific methods of experimentation or controlled comparison. In contrast, the belief in race, in the sense of biological subspecies of Homo Sapiens, lacks a tangible basis; indeed, it has been proven unsupportable genomically, behaviorally, and phenotypically.
Individuals and political groups have manipulated both God and race for nefarious purposes, but actions rooted in the human capacity to affiliate with non-kin, to cooperate, and especially to unite in love and respect for the agency of others has given rise to a variety of constructive social codes that facilitate intragroup and extensive intergroup harmony and mitigate disruptive personal and social behavior.
Whereas scientists possess the means to eliminate belief in human races, they lack the means to eradicate belief in God, and frankly they are probably wasting time and treasure on the exercise.
There’s an optimism here I found somewhat reminiscent of the Jesuit paleontologist Teilhard de Chardin, who had a very goal-oriented view of humanity and its role in cosmic evolution.
I could’t resist asking Tuttle whether Teilhard’s writings had any influence on his own thought as he embarked on his career in the 1960s. This was around the time that Teilhard’s writings were becoming most influential.
“Quite the contrary,” Tuttle replied in an email. “I thought Phenomenon of Man was rubbish. Father Teilhard wanted to be an evolutionary biologist while not giving up God. He did a shoddy job of reconciling deep religious belief with evolutionary biology…for one, he was an orthogenecist [i.e., he believed in progressive, directional evolution, toward a universal goal].”
“I cannot see a reconciliation of the two realms,” Tuttle added. “I believe in the power of love which some or many see as an aspect of God. But I do not think there is a celestial, etherial being that is interested in us or that makes good or bad things happen.”
Tuttle elaborated on this in a recent review he wrote for the American Journal of Psychology: “As a Christian participant observer into my late teens, followed by two decades attempting to be an atheist, and then participation in the music ministry at a wide variety of churches over the past 30 years, I aver that the bonding of congregations based on love of God and one another are substantive enough to withstand the sarcastic remarks and mockery of professed atheists who command notable space in print media and on the airways.”
Apes and Human Evolution is also available in Kindle Edition. But given the slight difference in price, I recommend getting the print edition.
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”.
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
Date: October 13, 2014
Source: University of Tennessee
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.”
- Vladimir Dinets. Apparent coordination and collaboration in cooperatively hunting crocodilians. Ethology Ecology & Evolution, 2014; 1 DOI:10.1080/03949370.2014.915432
Date: October 7, 2014
Source: Acoustical Society of America (ASA)
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.”
- 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
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 experiments, 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
Date: September 17, 2014
Summary: Of all of the world’s species, humans and chimpanzees are some of the only species to coordinate attacks on their own members. Since Jane Goodall introduced lethal inter-community killings, primatologists have debated the concept of warfare in this genus. New research from an international coalition of ape researchers has shed new light on the subject, suggesting that human encroachment and interference is not, as previous researchers have claimed, an influential predictor of chimp-on-chimp aggression.
Of all of the world’s species, humans and chimpanzees are some of the only to engage in coordinated attacks on other members of their same species. Jane Goodall was among the first to introduce the occurrence of lethal inter-community killings and since then primatologists and anthropologists have long debated the concept of warfare in this genus. Research theories have pointed to increased gains and benefits of killing off competitors and opening up increased access to key resources such as food or mates. In contrast, others have argued that warfare is a result of human impact on chimpanzees, such as habitat destruction or food provisioning, rather than adaptive strategies.
New research from an international coalition of ape researchers, published September 18 in the journalNature, has shed new light on the subject, suggesting that human encroachment and interference is not, as previous researchers have claimed, an influential predictor of chimp-on-chimp aggression.
The study began as a response to a growing number of commentators claiming that chimpanzee violence was caused by human impacts. “This is an important question to get right. If we are using chimpanzees as a model for understanding human violence, we need to know what really causes chimpanzees to be violent,” said University of Minnesota researcher Michael L. Wilson, lead author on the study.
“Humans have long impacted African tropical forests and chimpanzees, and one of the long-standing questions is if human disturbance is an underlying factor causing the lethal aggression observed,” explained co-author David Morgan, PhD, research fellow with the Lester E Fisher Center for the Study and Conservation of Apes at Lincoln Park Zoo in Chicago. Morgan has studied chimpanzees deep in the forests of Republic of Congo for 14 years. “A key take-away from this research is that human influence does not spur increased aggression within or between chimpanzee communities.”
A team of 30 ape researchers assembled extensive data sets spanning five decades of research gathered from 18 chimpanzee communities experiencing varying degrees of human influence. In all, data included pattern analysis of 152 killings by chimpanzees. The key findings indicate that a majority of violent attackers and victims of attack are male chimpanzees, and the information is consistent with the theory that these acts of violence are driven by adaptive fitness benefits rather than human impacts.
“Wild chimpanzee communities are often divided into two broad categories depending on whether they exist in pristine or human disturbed environments,” explained Morgan. “In reality, however, human disturbance can occur along a continuum and study sites included in this investigation spanned the spectrum. We found human impact did not predict the rate of killing among communities.
“The more we learn about chimpanzee aggression and factors that trigger lethal attacks among chimpanzees, the more prepared park managers and government officials will be in addressing and mitigating risks to populations particularly with changing land use by humans in chimpanzee habitat,” explained Morgan.
- Michael L. Wilson, Christophe Boesch, Barbara Fruth, Takeshi Furuichi, Ian C. Gilby, Chie Hashimoto, Catherine L. Hobaiter, Gottfried Hohmann, Noriko Itoh, Kathelijne Koops, Julia N. Lloyd, Tetsuro Matsuzawa, John C. Mitani, Deus C. Mjungu, David Morgan, Martin N. Muller, Roger Mundry, Michio Nakamura, Jill Pruetz, Anne E. Pusey, Julia Riedel, Crickette Sanz, Anne M. Schel, Nicole Simmons, Michel Waller, David P. Watts, Frances White, Roman M. Wittig, Klaus Zuberbühler, Richard W. Wrangham. Lethal aggression in Pan is better explained by adaptive strategies than human impacts. Nature, 2014; 513 (7518): 414 DOI: 10.1038/nature13727
Date: August 12, 2014
Summary: Whether or not humans are the only empathic beings is still under debate. In a new study, researchers directly compared the ‘yawn contagion’ effect between humans and bonobos — our closest evolutionary cousins. By doing so they were able to directly compare the empathic abilities of ourselves with another species, and found that a close relationship between individuals is more important to their empathic response than the fact that individuals might be from the same species.
Whether or not humans are the only empathic beings is still under debate. In a new study, researchers directly compared the ‘yawn contagion’ effect between humans and bonobos (our closest evolutionary cousins). By doing so they were able to directly compare the empathic abilities of ourselves with another species, and found that a close relationship between individuals is more important to their empathic response than the fact that individuals might be from the same species.
The ability to experience others’ emotions is hard to quantify in any species, and, as a result, it is difficult to measure empathy in an objective way. The transmission of a feeling from one individual to another, something known as ‘emotional contagion,’ is the most basic form of empathy. Feelings are disclosed by facial expressions (for example sorrow, pain, happiness or tiredness), and these feelings can travel from an “emitting face” to a “receiving face.” Upon receipt, the mirroring of facial expressions evokes in the receiver an emotion similar to the emotion experienced by the sender.
Yawn contagion is one of the most pervasive and apparently trivial forms of emotional contagion. Who hasn’t been infected at least once by another person’s yawn (especially over dinner)? Humans and bonobos are the only two species in which it has been demonstrated that yawn contagion follows an empathic trend, being more frequent between individuals who share a strong emotional bond, such as friends, kin, and mates. Because of this similarity, researchers sought to directly compare the two species. Over the course of five years, they observed both humans and bonobos during their everyday activities and gathered data on yawn contagion by applying the same ethological approach and operational definitions. The results of their research are published today in the peer-reviewed journal PeerJ.
Two features of yawn contagion were compared: how many times the individuals responded to others’ yawns and how quickly. Intriguingly, when the yawner and the responder were not friends or kin, bonobos responded to others’ yawns just as frequently and promptly as humans did. This means that the assumption that emotional contagion is more prominent in humans than in other species is not necessarily the case.
However, humans did respond more frequently and more promptly than bonobos when friends and kin were involved, probably because strong relationships between humans are built upon complex and sophisticated emotional foundations linked to cognition, memory, and memories. In this case, the positive feedback linking emotional affinity and the mirroring process seems to spin faster in humans than in bonobos. In humans, such over-activation may explain the potentiated yawning response and also other kinds of unconscious mimicry response, such as happy, pained, or angry facial expressions.
In conclusion, this study suggests that differences in levels of emotional contagion between humans and bonobos are attributable to the quality of relationships shared by individuals. When the complexity of social bonds, typical of humans, is not in play,Homo sapiens climb down the tree of empathy to go back to the understory which we share with our ape cousins.
- Elisabetta Palagi, Ivan Norscia, Elisa Demuru. Yawn contagion in humans and bonobos: emotional affinity matters more than species. PeerJ, 2014; 2: e519 DOI: 10.7717/peerj.519
Date: July 28, 2014
Source: University of Michigan Health System
Summary: Babies can learn what to fear in the first days of life just by smelling the odor of their distressed mothers’, new research suggests. And not just “natural” fears: If a mother experienced something before pregnancy that made her fear something specific, her baby will quickly learn to fear it too — through her odor when she feels fear.
Babies can learn what to fear in the first days of life just by smelling the odor of their distressed mothers, new research suggests. And not just “natural” fears: If a mother experienced something before pregnancy that made her fear something specific, her baby will quickly learn to fear it too — through the odor she gives off when she feels fear.
In the first direct observation of this kind of fear transmission, a team of University of Michigan Medical School and New York University studied mother rats who had learned to fear the smell of peppermint — and showed how they “taught” this fear to their babies in their first days of life through their alarm odor released during distress.
In a new paper in the Proceedings of the National Academy of Sciences, the team reports how they pinpointed the specific area of the brain where this fear transmission takes root in the earliest days of life.
Their findings in animals may help explain a phenomenon that has puzzled mental health experts for generations: how a mother’s traumatic experience can affect her children in profound ways, even when it happened long before they were born.
The researchers also hope their work will lead to better understanding of why not all children of traumatized mothers, or of mothers with major phobias, other anxiety disorders or major depression, experience the same effects.
“During the early days of an infant rat’s life, they are immune to learning information about environmental dangers. But if their mother is the source of threat information, we have shown they can learn from her and produce lasting memories,” says Jacek Debiec, M.D., Ph.D., the U-M psychiatrist and neuroscientist who led the research.
“Our research demonstrates that infants can learn from maternal expression of fear, very early in life,” he adds. “Before they can even make their own experiences, they basically acquire their mothers’ experiences. Most importantly, these maternally-transmitted memories are long-lived, whereas other types of infant learning, if not repeated, rapidly perish.”
Peering inside the fearful brain
Debiec, who treats children and mothers with anxiety and other conditions in the U-M Department of Psychiatry, notes that the research on rats allows scientists to see what’s going on inside the brain during fear transmission, in ways they could never do in humans.
He began the research during his fellowship at NYU with Regina Marie Sullivan, Ph.D., senior author of the new paper, and continues it in his new lab at U-M’s Molecular and Behavioral Neuroscience Institute.
The researchers taught female rats to fear the smell of peppermint by exposing them to mild, unpleasant electric shocks while they smelled the scent, before they were pregnant. Then after they gave birth, the team exposed the mothers to just the minty smell, without the shocks, to provoke the fear response. They also used a comparison group of female rats that didn’t fear peppermint.
They exposed the pups of both groups of mothers to the peppermint smell, under many different conditions with and without their mothers present.
Using special brain imaging, and studies of genetic activity in individual brain cells and cortisol in the blood, they zeroed in on a brain structure called the lateral amygdala as the key location for learning fears. During later life, this area is key to detecting and planning response to threats — so it makes sense that it would also be the hub for learning new fears.
But the fact that these fears could be learned in a way that lasted, during a time when the baby rat’s ability to learn any fears directly was naturally suppressed, is what makes the new findings so interesting, says Debiec.
The team even showed that the newborns could learn their mothers’ fears even when the mothers weren’t present. Just the piped-in scent of their mother reacting to the peppermint odor she feared was enough to make them fear the same thing.
And when the researchers gave the baby rats a substance that blocked activity in the amygdala, they failed to learn the fear of peppermint smell from their mothers. This suggests, Debiec says, that there may be ways to intervene to prevent children from learning irrational or harmful fear responses from their mothers, or reduce their impact.
From animals to humans: next steps
The new research builds on what scientists have learned over time about the fear circuitry in the brain, and what can go wrong with it. That work has helped psychiatrists develop new treatments for human patients with phobias and other anxiety disorders — for instance, exposure therapy that helps them overcome fears by gradually confronting the thing or experience that causes their fear.
In much the same way, Debiec hopes that exploring the roots of fear in infancy, and how maternal trauma can affect subsequent generations, could help human patients. While it’s too soon to know if the same odor-based effect happens between human mothers and babies, the role of a mother’s scent in calming human babies has been shown.
Debiec, who hails from Poland, recalls working with the grown children of Holocaust survivors, who experienced nightmares, avoidance instincts and even flashbacks related to traumatic experiences they never had themselves. While they would have learned about the Holocaust from their parents, this deeply ingrained fear suggests something more at work, he says.
Going forward, he hopes to work with U-M researchers to observe human infants and their mothers — including U-M psychiatrist Maria Muzik, M.D. and psychologist Kate Rosenblum, Ph.D., who run a Women and Infants Mental Health clinic and research program and also work with military families. The program is currently seeking women and their children to take part in a range of studies.
- Jacek Debiec and Regina Marie Sullivan. Intergenerational transmission of emotional trauma through amygdala-dependent mother-to-infant transfer of specific fear. PNAS, July 28, 2014 DOI: 10.1073/pnas.1316740111
A team of researchers working in South Africa have a sneaking suspicion that they’re being used as human shields. Monkeys who normally spend their time in trees avoiding predators like leopards and raptors seem to relax their vigilance a little around humans, venturing down to eat.
Humans, as well as human infrastructure, can alter the relationship between predators and prey by shielding one from the other. A stone wall filled with crevices could provide a refuge for a small critter, while a person’s presence might indirectly guard an animal against its would-be killer. Those who are used to us may actually begin to take more risks when we’re around.
To quantify this alteration in risk-taking behavior, Katarzyna Nowak of Durham University and colleagues tested the magnitude of the “human shield effect” on two groups of samango monkeys (Cercopithecus mitis erythrarcus) at a site with high natural predator density and no human hunting pressure.
Samango monkeys spend most of their time in trees avoiding predators on the ground, like large cats, and those in the canopies above, like birds of prey. They don’t stray very far, and they don’t climb too high. When observed by humans, however, the monkeys preferred to climb down to eat food from the forest floor. The work was published in Behavioral Ecology earlier this month.
The researchers set up feeding stations at various levels in the forest and looked at a fear measure known as “giving-up densities.” That’s the density of food remaining in a patch when a forager leaves. (It’s a little like, say, you were in a hurry and didn’t eat your whole burger.) With lots of predators at this site, the giving-up densities were greatest at ground level (0.1 meter) relative to the three tree canopy levels (2.5, 5, and 7.5 meters up). This highlights a strong vertical axis of fear, as they researchers say.
“The amount of food monkeys depleted from buckets over the course of the experiment varied with height, with the most food left uneaten at ground level, where there is a risk of predation by leopards and caracals,” Nowak tells The Independent.
When human followers were present, giving-up densities were reduced at all four heights. In one of the groups, the vertical axis totally disappeared in the presence of human observers. By passively keeping terrestrial predators away from the area, we seem to lower the monkeys’ perceived risks.
“When a human observer was following monkeys, they ate more food at every height, with the most notable differences at the bottom two levels,” Nowak explains. “Animals are expected to deplete more food where and when they feel safe [but] we had not expected human followers to have such strong effect!”
Publicado em 23.04.2014
Estou andando por uma rua e vejo uma amiga. A amiga não me vê, então eu grito: “Oi, Marina!”. Marina se vira e olha para mim. Isto é o que os humanos fazem: já que todos nós temos nomes, aprendemos uns os dos outros. Se a pessoa que eu vi é realmente a Marina, eu rapidamente me conecto a ela.
Os nomes são muito úteis, especialmente para uma espécie social como os seres humanos. Se você é um solitário – como um polvo ou um guepardo – e passa a maior parte de sua vida em esplêndido isolamento, os nomes não serão de grande ajuda. A maioria de nós, porém, usa nomes constantemente.
Há diferenças sutis entre nomes humanos e nomes animais. Sim, batizamos os nossos cães e quando chamamos: “Vem, Rex!”, ele vem. O Rex pode até reconhecer seu nome, mas é difícil acreditar que ele reconheça o nosso. Meu nome é Jéssica, mas eu não tenho ideia do que as minhas cachorras me chamam em suas mentes caninas. Porém, ao contrário do que eu pensava, nós, seres humanos, não somos os únicos que usam nomes pelos quais somos reconhecidos ao longo das nossas vidas.
O experimento dos cavalos
A autora científica Virginia Morell, em seu novo livro “Animal Wise”, descreveu um experimento envolvendo cavalos, no qual os relinchos dos animais foram muito parecido com nomes.
Ela fala sobre um cavalo chamado Silver. Ele está em sua tenda, cuidando de sua própria vida, quando os pesquisadores passam por ali com uma égua do rebanho de Silver. Silver olha para eles, vê Pepsi passar e volta a mastigar seu feno. Pepsi some atrás de uma barreira.
Agora vem a ciência. Os pesquisadores têm um gravador escondido atrás dessa barreira, onde Pepsi está silenciosamente parada. Algumas vezes, os pesquisadores tocam o relincho de Pepsi, que é o seu som de identificação. Quando ouve o som, Silver olha brevemente e depois volta a comer. Nada demais, o cavalo que acabou de passar bufou. Isso é de se esperar.
Contudo, às vezes eles tocavam um relincho diferente, de um cavalo diferente que Silver também conhece, mas que não passou por perto, que não deveria estar lá. Quando eles fazem isso, Silver olha para cima imediatamente, olha para a barreira e continua olhando por um longo tempo, como se dissesse: “O que está acontecendo? Eu vi a Pepsi. Mas essa não é a Pepsi”.
“Os cientistas fizeram este teste com vários cavalos e todas a vezes suscitaram a mesma resposta surpresa quando o cavalo ouvia alguém diferente de quem tinha visto”, conta Virgina.
O som dispara uma imagem na mente
Virgina cita o biólogo Karen McComb para explicar que isso mostra que o cavalo tinha uma expectativa. “Ele esperava ouvir o relincho do indivíduo que tinha acabado de passar, porém, ao invés disso, ouve outro animal. Isso significa que os cavalos têm imagens em sua mente dos cavalos que conhecem”.
Isso é um começo. Entretanto, quando os seres humanos usam nomes, fazemos mais do que isso. Muito mais. Em vez de apenas “Eu, Jéssica”, “Eu, Marina”, podemos dizer: “Oi, Marina. Quer almoçar?”. Será que algum animal também tem a capacidade de fazer isso? De usar um nome para começar uma conversa? A resposta é sim.
Considere o periquito mastrantero (Forpus passerinus), um passarinho verde adorável que vive na região da Colômbia, Venezuela e ao largo da porção brasileira do Rio Amazonas. O cientista Karl Berg construiu um monte de ninhos de papagaio em um rancho da Venezuela e instalou neles microcâmeras, gravando tudo que os animaizinhos fazem. Como você pode imaginar, eles piam muito.
Enquanto muita gente acha que isso tudo é só uma barulheira, o pesquisador aposta que os periquitos estão conversando. Berg ouviu tantos papagaios em tantos ninhos e por tanto tempo, que ele é capaz de identificar que semanas após o nascimento, esses pequenos pássaros começam a usar sons muito específicos para identificar-se entre si. Não só isso, eles aprendem os “nomes” de seus pais, irmãos, irmãs, e sabem usá-los na conversa.
De onde vêm os nomes?
Mas quem batiza esses papagaios? Será que a natureza dá a cada filhote um conjunto pré-programado de pios? “Uma possibilidade”, explica Berg a Virginia, “é que os pais estão nomeando seus filhotes, da mesma forma que fazemos com os nossos filhos”.
O vídeo abaixo (narrado por Cornell Mark Dantzker e com legendas disponíveis em tradução automática) mostra como Karl Berg fez o experimento que sugere fortemente que as mamães e papais papagaio escolhem os nomes de seus bebês.
O pesquisador trocou ovos de ninho para descobrir se os nomes eram um código genético ou aprendidos. Para isso, comparam o som dos filhotes quando atingiam a maturidade com os de seus pais biológicos e adotivos. A conclusão foi de que os sons eram mais parecidos com os dos pais adotivos, o que provaria que eles foram aprendidos durante o crescimento.
O livro de Virginia Morell revela que os seres humanos e os papagaios não são os únicos a usarem esse sistema. Os golfinhos têm cliques e assobios particulares que são nomes – nomes que, como nós, são usados em conversas casuais.
Aos poucos, os cientistas estão aprendendo a decodificar as conversas de animais muito diferentes, bichos que vivem vidas ricas em intrigas, planos, brigas, esquemas, romance, apetites. Um dia seremos capazes de acompanhar tudo isso e mesmo nos intrometermos na conversa chamando um papagaio, um golfinho ou um cavalo pelo seu nome “verdadeiro”. Já imaginou?
Seria como assistir a reality shows. Ao invés de “Mulheres Ricas”, veremos “As conspirações dos papagaios da Venezuela”, e todos nós vamos torcer para aquele chamado “Pip-de-pip-de-pi, pi, pi” ficar com a papagaia mais bonita. [NPR, Proceedings Of The Royal Society, Cornell Lab of Ornithology]
BY BRANDON KEIM
Orcas performing at SeaWorld San Diego. Image: z2amiller/Flickr
A California lawmaker has proposed a ban on keeping killer whales in captivity for purposes of human entertainment.
Announced today by Assemblyman Richard Bloom, D-Santa Monica, the Orca Welfare and Safety Act would outlaw SeaWorld-style shows, as well as captive breeding of the creatures. Violations would be punished by $100,000 in fines, six months in jail, or both.
No hearing has yet been scheduled on the proposal, which will require a majority vote to pass through legislature. It’s also unclear how much support the bill will have, though California has passed progressive animal legislation in the recent past, including bans on shark fin soup and hunting bears with dogs.
“There is no justification for the continued captive display of orcas for entertainment purposes,” Bloom said in a public statement. “These beautiful creatures are much too large and far too intelligent to be confined in small, concrete tanks for their entire lives. It is time to end the practice of keeping orcas captive for human amusement.”
Bloom’s proposed law isn’t the first of its kind: South Carolina banned the public display of dolphins in 1992, as did Maui County, Hawaii in 2002. In February of this year, New York state senator Greg Ball introduced a bill that would ban orca confinement in sea parks and aquariums.
Unlike those states, however, California is home to SeaWorld San Diego, where 10 orcas — roughly one-fifth of all captive orcas — are used in performances. “This is a huge state in which to have that ban,” said Lori Marino, a neurobiologist and founder of the Kimmela Center for Animal Advocacy.
In recent years, the experience of captive orcas has come under scrutiny by animal advocates and some scientists, who say that aquarium conditions are simply inappropriate for animals as big, intelligent and highly social as orcas.
As evidence, advocates point to the physical and mental problems of orcas in captivity: They’re short-lived, prone to disease, have difficulty breeding, display extreme aggression and in some cases appear to be emotionally disturbed.
Such was the case with Tillikum, an orca at SeaWorld Orlando who killed three people, including SeaWorld trainer Dawn Brancheau. Her death and SeaWorld’s orcas were the subject of Blackfish, a 2013 documentary that inspired Bloom’s measure, which was written with assistance from Blackfishdirector Gabriela Cowperthwaite and Naomi Rose of the Animal Welfare Institute.
SeaWorld San Diego did not reply to requests for comment, but in a statement, spokesman David Koontz criticized Bloom for “associating with extreme animal rights activists.”
Koontz said the bill reflected the “the same sort of out-of-the-mainstream thinking” as an infamous lawsuit, filed by People for the Ethical Treatment of Animals and dismissed in 2012, which invoked the United States Constitution’s slavery-abolishing 13th amendment as grounds for freeing SeaWorld’s orcas.
“We engage in business practices that are responsible, sustainable and reflective of the balanced values all Americans share,” wrote Koontz.
Andrew Trites, head of the University of British Columbia’s Marine Mammal Research Unit, said that misgivings about keeping whales and dolphins in captivity are not restricted to activists and extremists. They’re something many scientists grapple with.
“We think about this a lot,” he said, “I do understand the strong feelings of those who think it’s entirely wrong. I also understand the value of keeping them in captivity.”
Studying captive orcas can provide information about health and physiology that’s otherwise difficult to obtain, and can be used to benefit wild orcas, said Trites. “But it has to be about more than just entertainment,” he said. “They have to be serving some greater good.”
Marino noted that the bill allows research on orcas held for rehabilitation after being rescued from injury or stranding. Those orcas couldn’t be kept in aquariums, though, but rather in enclosed, shallow-water sea pens that are open to the public — a compromise, perhaps, between greater-good benefits and individual well-being.
Orcas now kept at SeaWorld would be returned to the wild or, if that’s not possible, also kept in sea pens.
If Bloom’s bill passes, it could inspire other such measures, said Marino. “The science is so overwhelming that members of the legislature are convinced, and are putting this out there,” she said. “This is historic.”