Posts Tagged ‘chimpanzees’
[LINK] “Lab chimps successfully treated with anti-depressants”
Via io9 I came across Pallab Ghosh’s BBC report suggesting that anti-depressants could be quite useful for chimps freed from research colonies. With the obvious provisos that this has to be done carefully, under controlled conditions, if this report is accurate I’m pleased. Especially after reading Andrew Westoll’s award-winning book The Chimps of Fauna Sanctuary: A Canadian Story of Resilience and Recovery, describing how chimps at a rehab facility in Québec suffered terribly and in ways recognizable to humans from their long captivity, and in light of things like the National Institutes of Health’s retirement of its chimp colonies, doing something to help these intelligent animals seems morally imperative.
Dr Godelieve Kranendonk, a behavioural biologist leading the study at AAP, a rescue centre for animals in the Netherlands, told BBC News that the results had been astonishing.
“Suddenly, [the chimps] woke up. It was as if they were zombies in their enclosures and now they are happy, playing with each other. They are chimps again – that was really nice to see,” she told me.
[. . .]
Staff at the AAP sanctuary care for the animals until they die. They try to rehabilitate them so that they can live out their remaining years happily.
The chimps are fed a good diet of vegetables, have toys and plenty of space in which to play. But Dr Kranendonk found that the abnormal behaviour actually increased. It was as if the animals did not know how to cope with their new found freedom.
Dr Kranendonk decided to consult Martin Bruene, a professor of human psychiatric disorders at the University of Bochum, Germany. He prescribed a course of anti-depressants for five of the chimps.
All the animals had been used in medical experiments and were infected with Hepatitis C. “Willy” showed the least abnormal behaviour. “Tomas” and “Zorro”, on the other hand, would spend a third of their waking hours eating their own vomit.
“Iris” had lost so much weight from vomiting when she first came to the sanctuary that the staff thought she would die.
The most troubled though was “Kenny”, a small chimp who was constantly anxious that the others would attack him and spent much of his time screaming in terror.
The chimps were given SSRI (Selective Serotonin Reuptake Inhibitors), which is a class of anti-depressant similar to Prozac and is used to treat human patients for depression, anxiety disorder and obsessive compulsive disorder.
After six to eight weeks, the animals behaviour started improving. The abnormal behaviour declined and the chimps began to play together. After seven months, there was a vast difference.
[. . .]
The big question though is whether the effect lasts when the chimps are taken off the medication. The early indications are promising. The medication has been steadily reduced and there has been no adverse effect on the chimps’ behaviour.
Kenny himself decided that he did not want to take the anti-depressants anymore. His clownish behaviour has continued.
“It seems that while on the medication, the chimps learn to be chimps again,” said Dr Kranendonk. “And once they have learned that, they don’t need the medication any more.”
[LINK] “NIH Told to Retire Most Research Chimps”
This news reported by Scientific American is good news, contingent of course on the chimpanzees being properly housed and cared for after the experiments are done.
The US National Institutes of Health (NIH) should dismantle a decades-old colony of 360 chimpanzees, retiring all but roughly 50 of the animals to a national sanctuary, the biomedical agency was told on 22 January in a long-awaited report.
The report, from a working group of external agency advisors, also counsels the NIH to end about half of 21 existing biomedical and behavioral experiments, saying they do not meet criteria established in a December, 2011 Institute of Medicine (IOM) report.
“Clearly there is going to be a reduction in the use of chimpanzees in research,” says working group co-chair Kent Lloyd, the associate dean for research at the School of Veterinary Medicine at the University of California, Davis.
The report says that the NIH should begin planning sanctuary housing for the retiring animals “immediately”, and that a colony of about 50 animals would be sufficient for future research. The report also sets high hurdles for new chimpanzee experiments in the future, calling for the establishment of an independent committee that would vet individual study proposals after they first pass routine NIH scientific review. In cases where the burden on the animals is high, the benefit to humanity should have to be “very high” to pass muster with the committee, says Daniel Geschwind, the other co-chair of the working group and a geneticist at the School of Medicine at the University of California, Los Angeles.
The report suggests that three of nine ongoing invasive experiments, involving immunology and infectious diseases, could continue, because they meet the IOM criteria. These require that a study be needed for public health; that no alternative animal model exists; that performing the study in humans would be unethical; and that the animals be maintained in socially and physically appropriate habitats. The report also says that eight of 13 behavioral or comparative genomics studies could be allowed to continue, but in some cases only conditionally — meaning that funding for these experiments could not be renewed without passing the independent committee review.
The working group — a subgroup of NIH’s Council of Councils, a trans-agency advisory body — was chartered by NIH director Francis Collins one year ago to advise the agency on how to implement the recommendations of the IOM report, which found that most chimpanzee research was not necessary. Its recommendations are not binding; Collins is expected to respond to them in late March, after a 60-day period of public comment. But they signal yet another significant step in an ongoing retrenchment. Last month, the agency announced that it will retire 110 chimpanzees to the national Chimp Haven sanctuary in Keithville, Louisiana, after they had been first slated to move to an active NIH-supported research centre in San Antonio, Texas.
[LINK] “Chimps Might Have a Sense of Fair Play”
Michael Balter’s ScienceNOW article highlights yet another commonality between humans and our nearest cousins, the chimpanzees. There’s some question regarding the findings, described elsewhere in the article, but the conclusions seem plausible.
When economists and psychologists want to test fairness in humans, they turn to the Ultimatum Game. Typically, one subject, called the “proposer,” is given a sum of money to divide with a “responder.” If the responder accepts the proposer’s offer, both are rewarded. But if the responder rejects the offer, both get nothing. Although results vary, human proposers usually offer about 40 percent to 50 percent of the money, and responders reject offers that are under 20 percent — even though they will end up with nothing for doing so. Researchers interpret both behaviors as evidence for a basic sense of fairness.
In 2007, a team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, tried the Ultimatum Game on chimps. In a simplified version of the game, the team gave the chimps set options about how to divvy up dishes of raisins, such as a 50-50 split or an 80-20 split. The proposer, in a cage next to that of the responder, made an offer by pulling a tray halfway toward the responder. The responder had to choose between pulling it the rest of the way so that both chimps could get the food or refusing to pull it at all, in which case both chimps got nothing. In contrast with humans, chimps rarely rejected offers of 20% of the food; they only rejected such tenders in experiments where the proposer had the additional choice of taking all of the food and leaving the responder with nothing. The team concluded that the responders would accept even the meanest split as long as they got something, suggesting that unlike humans, they were not offended by blatantly unfair offers.
Some researchers pounced on the study, however, suggesting that chimps couldn’t be expected to play fair given the conditions of their captivity, which had taught chimps that they had little control over how much they got to eat, or that they might not be able to understand the complicated tray-pulling apparatus.
To try to resolve the debate, a team led by primatologist Frans de Waal of Emory University in Atlanta has developed what it considers a more chimp-friendly version of the Ultimatum Game. In previous work, de Waal and his co-workers had established that chimps could be trained to exchange tokens for food. In the new study, published online this week in the Proceedings of the National Academy of Sciences, de Waal and his colleagues trained six chimps to recognize that such colored tokens, made of short pieces of plastic pipe, represented one of two ways of dividing six banana slices: an equal 3-3 split or an unequal 5-1 split (see video). The proposer chimp chose one of the tokens and then handed it through the wire mesh of its cage to a responder chimp, which had to give it to a human experimenter for both chimps to get the food. In essence, the tokens served as money that could be exchanged for the banana slices.
The chimps seemed to be playing fair. The percentage of equitable (3-3) offers ranged from 58% to 92%, much higher than in the Leipzig study which averaged about 25% for such 50-50 splits. However, as in the Leipzig study, the chimps never rejected “unfair” offers of 5-1 splits.
The team concluded that a sense of fairness arose sometime before the chimp and human lines split some 5 million to 7 million years ago, and that doing right by others has a long evolutionary history. “When we see this kind of behavior in humans, we call it fairness,” says the study’s lead author, psychologist Darby Proctor, now of Emory University, who adds that researchers shouldn’t “hesitate to call it fairness in chimps.”
[LINK] “Chimps Have Geniuses, Too”
ScienceNOW’s Sarah C.P. Williams reports on recent research suggesting that, among chimpanzees as among humans, intelligence is variable, with not only different individuals evidencing different levels of intelligence but individuals being better at evidencing some skills than others.
Natasha, a chimp at the Ngamba Island Chimpanzee Sanctuary in Uganda, has always seemed different from her peers. She’s learned to escape from her enclosure, teases human caretakers, and scores above other chimps in communication tests. Now, Natasha has a new title: genius. In the largest and most in-depth survey of chimpanzee intelligence, researchers found that Natasha was the smartest of the 106 chimps they tested—a finding that suggests that apes have their geniuses, too.
“Natasha was really much better than other chimps,” says biologist and first author of the new study Esther Herrmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.
Herrmann and her colleagues had previously tested chimps in a study designed to compare the skills of the animals with those of human children. During the study, they noticed a wide range of skills among the chimps and wondered whether they could measure this variation in ability—and whether there were studies that could predict the chimps’ overall performance in all areas, like an IQ test in humans. So they gave a battery of physical and social tests to 106 chimps at Ngamba Island and the Tchimpounga chimpanzee sanctuary in the Republic of the Congo, and to 23 captive chimpanzees and bonobos in Germany. In one experiment, chimps were asked to find food in a container after it had been shuffled around with empty containers. In another, they had to use a stick to get food placed on a high platform. The researchers analyzed the data to determine if the scores in some tests helped predict performance in others.
“In general, we don’t find any kind of general intelligence factor that can predict intelligence in all areas,” Herrmann says. “But we did find a big variation overall, and this one outstanding individual.”
The stand-out individual, Natasha, was the chimp that caretakers—who don’t administer tests to the chimps but do feed them, clean their cages, and accompany them on walks—consistently ranked as the smartest based on only the way she interacted with them. But there’s nothing about Natasha’s life—extra attention or time spent with humans, for example—that explains how she became so astute. “Motivation and temperament probably play a role,” Herrmann says. “That’s something that we want to look more into.”
In general, apes that were good in one area—such as tests requiring creative tool use—were not necessarily good in another—such as copying the actions of a test-giver to get a reward, the team reports this week in the Philosophical Transactions of the Royal Society B. But continuing to add new challenges to the battery of tests still could lead to a standardized intelligence factor, Herrmann says.
[LINK] “Tool-Making Bonobos Give Glimpse of Human Origins”
Wired Science’s Brandon Keim has more on tool-using bonobos.
Unlike their chimpanzee cousins, bonobos — formally known Pan paniscus to the chimps’ Pan troglodytes — have shown limited toolmaking ability, and are better known for their relatively gentle, highly amorous natures. Yet that doesn’t mean bonobos are intrinsically incapable of tool use, which anthropologists consider to be a crucial cognitive benchmark. Their potential may simply have gone untapped.
Roffman and colleagues worked with Kanzi and Pan-Banisha, a pair of bonobos living at the Great Ape Trust, who in the 1990s had been taught to shape tools from flint. In the new study, published Aug. 21 in Proceedings of the National Academy of Sciences, the two bonobos are described using those techniques decades later to crack open food-filled logs used as research substitutes for marrow-rich bones.
Holding a flint core in their right hands and hammer stones in their left, both bonobos made small, sharp-edged scrapers. Kanzi, the handier of the pair, also made choppers, wedges and drills. Altogether, his toolset resembled the famous implements made 2.6 million years ago by ancestral dwellers of what is now the Olduvai Gorge in Tanzania. Indeed, the marks left by Kanzi’s tools on his logs were strikingly similar to wear patterns seen in ancient butchered bones.
“Only early Homo was thought to produce such tool use markings,” wrote Roffman’s team. “Here we report that present-day Pan also has such competencies.”
“What is interesting here is that they use these tools for specific actions that could have been performed by our ancestors, like digging for food underground or extracting bone marrow,” said primatologist Thibaud Gruber of Scotland’s University of St. Andrews, who also studies bonobo tool use. He called the results “an important finding,” underscoring the likelihood that the last common ancestor of bonobos, chimps and humans possessed toolmaking abilities.
As Gruber and the study’s authors pointed out, Kanzi and Pan-Banisha are no ordinary bonobos. Aside from their tool-making training, they’ve lived around humans their entire lives, and use pictorial symbols to engage in complex dialog with their human handlers. Kanzi and Pan-Banisha’s level of toolmaking sophistication probably doesn’t exist in wild bonobos.
Yet rather than being a caveat, that may be a central lesson of the results, said primatologist Sue Savage-Rumbaugh, a study co-author and head scientist at the Great Ape Trust. Other bonobos can make stone tools, but it’s these two individuals, whose vocabulary includes 480 word symbols and who understand thousands of English words, who make tools best.
[. . .]
According to Savage-Rumbaugh, present-day Pan, both bonobos and chimpanzees, possess that cognitive advance. Whether it’s readily apparent is simply a function of circumstance. “The proper cultural and ecological conditions could serve to bootstrap a complex stone tool technology in Pan,” she said.
Findings like these drive home the importance of protecting chimpanzees and bonobos, which in the wild are going extinct, said Roffman. We’re literally preserving a living piece of our own heritage. “We have looked to the stars searching for contact with intelligent beings,” he said. “However, they have been with us all along, and are called Pan.”
[LINK] “Stone-Throwing Chimp Thinks Ahead”
Michael Balter’s ScienceNOW is another interesting data point.
Three years ago, a stone-throwing chimpanzee named Santino jolted the research community by providing some of the strongest evidence yet that nonhumans could plan ahead. Santino, a resident of the Furuvik Zoo in Gävle, Sweden, calmly gathered stones in the mornings and put them into neat piles, apparently saving them to hurl at visitors when the zoo opened as part of angry and aggressive “dominance displays.”
But some researchers were skeptical that Santino really was planning for a future emotional outburst. Perhaps he was just repeating previously learned responses to the zoo visitors, via a cognitively simpler process called associative learning. And it is normal behavior for dominant male chimps to throw things at visitors, such as sticks, branches, rocks, and even feces. Now Santino is back in the scientific literature, the subject of new claims that he has begun to conceal the stones so he can get a closer aim at his targets—further evidence that he is thinking ahead like humans do.
The debate over Santino is part of a larger controversy over whether some humanlike animal behaviors might have simpler explanations. For example, Sara Shettleworth, a psychologist at the University of Toronto in Canada, argued in a widely cited 2010 article entitled, “Clever animals and killjoy explanations in comparative psychology,” that the zookeepers and researchers who observed Santino’s stone-throwing over the course of a decade had not seen him gathering the stones, and thus could not know why he originally starting doing so. Santino, Shettleworth and some others argued, might have had some other reasons for caching the stones, and the stone throwing might have been an afterthought.
In the new study, published online today in PLoS ONE, primatologist Mathias Osvath of Lund University in Sweden—author of the earlier Santino paper—teams up with Lund University primatologist Elin Karvonen to report new observations of Santino’s behavior during 2010. Santino’s first attempts to throw stones during 2010 came during the May preseason. As a zoo guide led visitors toward Santino’s island compound, the chimpanzee began to engage in a typical dominance display: screeching, standing on two feet, and carrying a stone in his hand. The guide and the visitors retreated before Santino began hurling the stones, and then advanced again for a total of three approaches. When the people returned about 3 hours later, Santino advanced toward them, holding two stones, but he did not act aggressively, even picking up an apple from the water surrounding the island and nonchalantly munching on it. But when Santino got within close range, he suddenly threw one of the stones. (It didn’t hit anyone.)
The next day, Santino again threatened visitors with stones, but the group again backed away to avoid being hit. Santino was then observed pulling a heap of hay from inside his enclosure and placing it on the island close to where the visitors approached. He put several stones under the hay and waited until the group returned about an hour later. Then, without performing a dominance display, Santino pulled a stone from under the hay and threw it. Later, he pulled a stone that he had apparently hidden behind a log and tried to hit the visitors with that, as well.
Over the course of the summer, Osvath and Karvonen observed repeated episodes of this behavior, and also recovered stones that Santino had hidden under hay or logs, racking up 114 days of observation. They recovered a total of 35 projectiles that Santino had apparently concealed: 15 under hay heaps, 18 behind logs, and two behind a rock structure on the island. The researchers conclude that Santino deliberately engaged in deceptive concealment of the stones, and that this was a new, innovative behavior on his part: Before 2010, Santino had never put stones under hay piles or behind logs.