Studying gorillas in the Zoo and the wild

Unknown to most of our visitors, Zoo Atlanta has an active primate behavior and cognition research program, with scientists studying both wild apes and apes in zoological settings. As home to 20 gorillas and 11 orangutans, our zoo is able to look in depth at topics varying from memory and learning to zoological care to great ape health and aging. To manage the day-to-day demands of our research programs, the Zoo relies on two full-time primate research interns – that’s us! Our responsibilities fall under three principal areas of focus: the cognitive research, the behavioral observations, and our work with the Dian Fossey Gorilla Fund International.

A large part of our jobs is to study the behavior and cognition of the great apes living here at the Zoo. All sorts of primates call Zoo Atlanta home, but the great apes are of particular interest because they are our closest living relatives. Humans are classified as great apes along with chimpanzees, bonobos, gorillas and orangutans – this means that whenever we learn about their minds and their behavior, we are automatically learning about ourselves. We are that closely related! By studying our closest living relatives, we can also learn more about how our own species evolved.

To learn more about human and non-human ape minds, scientists at Zoo Atlanta study how orangutans and gorillas think, learn, and remember information. Using large touch-screen computers similar to your smartphone or tablet, the apes participate in research puzzles; when they get a question correct, a healthy treat pops out of the computer. They learn the rules of the puzzle through trial and error, trying to figure out how to get the most treats. While they work on the puzzles, the computers they’re using record their answers, their mistakes, and how long they take to complete the puzzle – these data help us figure out how the orangutans and gorillas are using their memory to solve the problems. We can then compare the great apes’ performance on these puzzles to that of monkeys or humans completing the same or similar puzzles. We gain a better understanding of how our own species thinks and learns, and the non-human apes benefit as well – they get to play on a computer that gives them treats!

Another area of focus of our research at Zoo Atlanta is the study of great ape behavior. For over two decades, our research department has studied the behavior of the western lowland gorilla, Gorilla gorilla gorilla. (Yes, that is in fact their scientific name. You can’t get easier than that – say gorilla three times and you’ve got it!) You can often see one of the primate research interns standing above the gorilla habitats, scribbling away on clipboards and intently watching the gorillas’ every move. If you hear a timer go off near the gorilla habitats, you aren’t just imagining things – you’re hearing an integral part of what we call behavioral sampling. Though we would love to, it is unrealistic to try to observe and record the behavior of 20 gorillas 24/7 for 365 days a year. Instead, we record behaviors during set time intervals reinforced by a stopwatch. So every two minutes, for example, we scan the habitat and write down what every gorilla was doing at that moment. This is called scan sampling. Some of our behavioral observations use what’s called focal sampling; these types of observations focus on the behavior of one individual instead of the whole group. Some important behaviors, however, are usually too brief to reliably land on the moment when the timer goes off – we write down such behaviors as grooming, playing, or aggression whenever they occur, giving this method the name all-occurrence sampling.

Currently, we house all 20 of the gorillas in five different groups. Zoo Atlanta is home to three bachelor groups, one family group, and one geriatric group. There is a wide range of ages, sexes, and personalities with the gorillas. Due to the variety of gorillas, there are nuances of observations between the groups. Specific questions direct how and what information we collect according to standardized protocols. For example, our geriatric group’s observational records include a map of their habitat where we can mark their location during an observational session. This information can help us assess health and welfare through their movement and habitat use.

Zoo Atlanta is particularly proud of its partnership with the Dian Fossey Gorilla Fund. For over 20 years, the Fossey Fund has based its U.S. headquarters here at Zoo Atlanta. By providing pro-bono office space, technical and administrative support, and volunteers, the Fund’s collaboration with the Zoo has allowed us to focus its resources on what matters most – conserving gorillas in the wild. As primate research interns, we split our time between the Fossey Fund and Zoo Atlanta, contributing to the research efforts of both organizations – another perk of the partnership. Although we aren’t in the field studying wild gorillas, we are able to help the Fund improve and maintain their extensive database; the Fossey Fund has over five decades’ worth of data from daily observations of mountain gorilla behavior, so there is a lot of information to keep organized and accessible.

But the most essential of all our collaborations often goes unsung. None of this research would be possible without the cooperation of some of the most intelligent, mischievous, curious, and extraordinary individuals we’ve ever had the privilege of working with. From the gorillas’ utter indifference to our inordinate attention during behavioral observations to the orangutans’ patience (and impatience) when we set up their computers, the participation of the apes makes all of our work possible.

Avery Twitchell-Heyne, Primate Research Intern, Dian Fossey Gorilla Fund International, and Liam Kelly, Primate Research Intern, Zoo Atlanta

(photo by Rand Lines)