On one side of the glass, an 11-year-old male hamadryas baboon sits on a miniature hillside. He sits some more. He sucks on his right hand, then cleans the toes on his right foot, which rests on an artificial rock.
On the other side, a 15-year-old male Homo sapiens clicks his stopwatch, smoothes his notebook and begins to write.
The human is Henry Lim, winner of a 2011 Young Naturalist Award from the American Museum of Natural History for his study of primate behavior. His subjects: the baboons at the Prospect Park Zoo in Brooklyn, star attractions with child-delighting, supersize, bubble-gum-colored rumps and familiar-looking family dynamics.
Henry, a rising junior at Baruch College Campus High School in Manhattan who lives on the Upper East Side, made two major findings.
One is that despite the countless differences between their native Ethiopian highlands and their 4,000-square-foot enclosure filled with toys, pools and waterfalls in Brooklyn, baboons engage in most of the same behaviors in captivity that they do in the wild — run, walk, play, groom, forage, hug.
The other is that the baboons in Brooklyn spend an awful lot of time seemingly doing nothing.
“My hypothesis was that grooming would be the most common behavior,” Henry said. “I had read that grooming helps make better relations because if you groom someone maybe they groom you back.” The data showed otherwise. “After many days watching them, sitting occurred the most.”
In any given minute, Henry found, there is a 60 percent chance that a baboon will spend time sitting, and only a 48 percent chance that a baboon will groom itself or another.
“I thought it would be a lot more exciting,” Henry said of his 24 hours of observation spread over six days last year. “I assumed that they’d be more active, like what monkeys usually do.”
Henry agreed to demonstrate his research technique with a visit to the zoo on a recent Tuesday afternoon.
The afternoon troop is a six-baboon unit: Simen, 20 years old, the alpha male; sisters Kobo, 35, and Mikele, 34; Matara, 15, a female; Moja, 11, Simen’s son by Matara; and Binti, 7, Simen’s daughter by Matara.
On the grass beside a waterfall, Matara sat patiently picking through the fur of another female, pulling off bugs.
A man with a toddler turned to Henry. “What’s she doing over there, eating them?” the man said.
“She’s eating them,” Henry replied. Zoo officials later confirmed that baboons eat the bugs they pull off one another.
Then Simen, the big one with the wise-looking whitish mane, walked over to one of the females and appeared to be trying to initiate some sort of contact. She responded by turning away from him and wandering off.
“Maybe he’s trying to get her to groom him,” Henry said. “He always gets near the other baboons, and they sometimes walk away from him. I never see Simen being groomed by anyone except himself.”
In his research — conducted through a program for students run by the natural history museum’s National Center for Science Literacy, Education and Technology — Henry worked from a list of 67 baboon behaviors observed in the wild in Africa by Larissa Swedell, an anthropologist from Queens College. The behaviors include “approach,” “look,” “grunt,” “lip smack,” “carry on back,” “genital inspect,” “eyebrow raise,” “short running attack,” “grimace,” “sleep” and the like.
Henry observed 57 of those behaviors, though his sample pool was different: Dr. Swedell tracked only females, while Henry tracked males and females both. The only behaviors he did not see were mating and fighting behaviors; he said the former did not take place because none of the females seemed to be in heat, and the latter were absent because the baboons have been split up into two troops, eliminating competition.
Henry got out his stopwatch to conduct a formal observation of Moja, who is darker and a bit smaller than his father. At one point he retired to a higher rock, sat, rubbed his nose, and looked up at the sunny sky. Henry completed his observations:
2:30: Sitting/shake fur
It was nearly 4 p.m., the end of the display day for the baboons. An unseen voice called them, and one by one they filed off stage. The young scientist gathered up his notebook and headed for the train.