A female gorilla on exhibit at the Bronx Zoo, with plucked patches on her forearms and knees.

I used to have nightmares about showing up days late for exams. Or of one really tall and one really short man looking for me in a lemon orchard. Don’t ask me why. But now I only have nightmares about getting things wrong. In writing.

This just happened. So here is the retraction. In the Of Mice and Mania article that I wrote about hair-plucking (or trichotillomania) in humans and other animals for Cabinet Magazine, I wrote that two young gorillas (Joe and Okie) brought the plucking behavior with them to the Franklin Park Zoo in Boston. Turns out that they didn’t. A male named Kit was already there, already plucking and came to the zoo plucking in the first place. Joe and Okie started plucking after spending time with him. Why on earth does this matter?

Because the keeper staff at a place like the Franklin Park Zoo need me to get it right. No one wants to be blamed for letting such a behavior develop unchecked in one’s charges. The problem is that keeper staff can’t really help it. Sometimes a gorilla (or parrot, or cat, for that matter) will pluck even if they seem to be fine in all other ways. So looking at plucking alone as a measure of animal happiness doesn’t get you very far. Temple Grandin wrote about this very thing (well not plucking, but about other repetitive behaviors like pacing) in Animals Make Us Human and brought up a very good point. It could be that the pacing tiger or the plucking ape, may actually be better off than their non-pacing non-plucking cage-mate. She argues that the behavior may be engaging their mind in a way that sitting still and doing nothing may not be. Furthermore, an animal who plucks or paces now, may have developed the behavior a long time ago as a self-soothing mechanism and the behavior itself has endured well after the stressful situation has passed.

That being said, a gorilla or cat or parrot or human who is too contented doing other things to pluck, is ideal. In Kit’s case, he was born at the Audobon Zoo in New Orleans. But both of his parents were born at Yerkes Primate Research Center in the mid-1970s. I hear his parents were pluckers too but I haven’t confirmed it. There is a documentary though, about life at Yerkes in the mid-1970s for the gorillas, chimps, and others who lived there and were being used for breeding and psychological studies. It’s called Primate.

Yerkes the man, a psychobiologist, ethologist, and sometimes-eugenicist who founded the research center in the 1920s, has a long and complicated history of working with primates in the United States. Donna Haraway has a wonderful essay about him in Primate Visions. His first gorilla was Congo.

Photos of Congo From Yerkes’ Mind of a Gorilla: Part 1. Published in 1927. Page 51.

In 1925, Congo arrived in the United States. She was the first mountain gorilla in the US and became an experimental subject for Yerkes (here she is using a stick at his first facility in Florida). For more on Congo and Yerkes, check out ‘Infinite Loneliness’: the life and times of Miss Congo, a paper by Georgina Montgomery.