Pet Chimpanzees Suffer Behavioral Problems for Years After Human Contact

Could chimpanzees raised in captivity be suffering because of it? Although there are immediate welfare consequences of removing infant chimps from their mothers, there's been very little research done on the long-term impacts of this early life experience. Now, scientists have taken a closer look at the behavioral and social impacts that chimps experience when raised in captivity.

In this case, the scientists studied 60 chimps with a range of personal histories over the course of 14 months. All of the chimpanzees were living in zoos and 35 of them were either former pets or performers.

"Unusually for a study on this topic, we looked at the degree of human and chimpanzee exposure on individual chimpanzees along a continuum," said Steve Ross, one of the researchers, in a news release. "This showed that those chimpanzees with more atypical beginnings to their lives, spending much more time with humans than with their own species, tended to behave differently than those that stayed with their family through infanthood."

In fact, the researchers found that chimps that were raised primarily around humans with less experience around their own species during the first four years of life tended to show reduce social competencies as adults.  More specifically, chimps with high human exposure engaged in less social grooming with their groupmates, and these effects were expressed years and sometimes even decades after their lives as pets and performers were over.

"One of the startling aspects of these findings is that these behavioral effects are so long-lasting," said Ross. "Chimpanzees which have found new homes in accredited zoos and good sanctuaries continue to demonstrate behavioral patterns that differentiate themselves from more appropriately-reared individuals. As a result, the process of integrating them with other chimpanzees can be challenging, stressful and even dangerous at times."

The findings reveal a bit more about what steps might need to be taken to ensure the survival of chimps as a species. Not only that, but the study adds to a growing body of evidence against owning chimps as pets.

The findings are published in the journal Peer J.