A few people have commented asking questions about George’s lack of hair in places, particularly on his lower arms. This is due to a combination of over-grooming himself and others in his new group enthusiastically grooming him.
Because George came from West Coast Game Park Safari, a roadside zoo that was open to anyone who paid the entrance fee, we do have some photos of him when he was younger. Some of them were found on the internet and some were sent to us by caring people when they found out that George had been moved to Chimpanzee Sanctuary Northwest. These older photos show varying states of hair loss in the same pattern. This indicates that he over-groomed himself starting at a very young age. Here are a few photos:
He had this same patterned hair loss when he arrived at the sanctuary, though it wasn’t as pronounced.
Now in his group of seven, all six other chimpanzees also groom him, and some of them like to pluck hair when grooming others. We’ve written before about grooming being a crucial aspect of chimpanzee social behavior. Chimpanzees especially love to groom scabs, which are much more visible on bare patches of skin.
George has a particular ingrained habit of self-grooming his shoulder with his opposite arm crossed over his chest. He’s doing this in almost every video that I’ve seen of George at the roadside zoo. He still does that here, but not as often as he did when he first arrived. You may have noticed there was a small sore on George’s shoulder from the video on Friday of his 1-year arrival anniversary party. That little wound has healed multiple times, only for the scab to be groomed off and the sore opened up again. It’s a very minor wound, but we are keeping an eye on it, just as his chimpanzee friends are.
Over-grooming / hair plucking can be a sign of anxiety, discomfort, or boredom, and it can also be a self-soothing behavior that developed during a particular period in life and persists as a habit throughout a chimpanzee’s life, well after the original stressor that prompted the behavior is gone.
Annie has a similar over-grooming pattern on her forearms, which is more pronounced some times than others.
Research has found that hair plucking is a very common behavior in captive primates. This study, for example, found that hair plucking was observed in 75% of the primates within the study group. This is part of the reason we don’t feel that chimpanzees belong in captivity. It’s impossible to give them an environment will all the opportunities to live as they evolved to as a species, even in the most enriched captive setting.
Thank you for asking about George’s bare arms. I hope this helps provide an explanation. We’re certainly interested to see if he will still be over-grooming or be over-groomed by others a year from now. Hopefully we will see him reciprocate grooming with his chimpanzee friends in the near future – that’s still something he hasn’t done!
