This update was written by primate keeper Melba Brown.
Last week, western lowland gorilla mother Calaya celebrated a big birthday: her sweet 16! On Aug. 30, the primate team threw Calaya and her troop—21-week-old Moke, Baraka, Mandara and Kibibi—a celebratory bash, the centerpiece of which was a colorful ice cake made by the talented team in our Department of Nutrition Sciences. Moke clearly enjoyed exploring the extra enrichment items scattered throughout the yard and sported a pink muzzle after indulging in some of the tasty treats.
After my last #GorillaStory update, we received a question on social media as to whether keepers have an opportunity to interact directly with Moke. We do—although it is always through a mesh safety barrier and at Calaya’s discretion.
With all of our gorillas, we practice positive reinforcement training. This means that participation in training sessions is voluntary, and a reward—either verbal praise or a favorite food item—is given to the gorilla once he or she has completed the correct behavior. When I interact with Moke, I say the name of the body part I am touching: head, foot, hand, nose, leg, belly and ear. This play is comparable to preschool training and has purpose.
We routinely ask our gorillas and orangutans to present their body parts for inspection so we can check for any injuries, cuts or scrapes that may need medical attention. When Moke is old enough to participate in husbandry training, he will be ahead of the game. For now, we keep these interactions to a minimum to encourage him to socialize with his family troop.
I get a big reaction out of Moke whenever I tickle his belly—he seems to love this and other play behaviors. He continues to make strides in perfecting his “display.” He quickly brings his arm across his chest, gets an animated look in his eye, and bounces around a bit before toppling over. He is very vocal and has a distinctive, piglet-like grunt that is a most charming sound!
The relationship between Calaya and Kibibi has taken a positive turn in the past week, and the tension between them seems to be decreasing. With Calaya’s approval, Kibibi and Moke have had several play bouts. Behaviorally, Kibibi has made a significant adjustment during these sessions to placate Calaya. She stretches out on the hay, thereby making herself smaller and submissive. When Moke walks to her, she plays with him in this low-lying position. This change demonstrates just how clever gorillas can be. Kibibi found a way to play with Moke and keep Calaya content.
Moke is teething, so I gave him a durable enrichment item to mouth: a Nylabone. Before he could get to it, Calaya took it and played with it while shaking her head back and forth. At one point, she tapped the bone on Moke’s head before positioning it between her hands and clapping multiple times. When she relinquished the toy, Moke was able to hold the bone and play with it. Not long after, Kibibi joined in on the fun.
Keepers at the Smithsonian’s National Zoo are experts in animal behavior, and one of my favorite activities is observing the gorillas and learning all I can about them. Gorilla group dynamics run the behavioral gamut!
Hints of the social hierarchy within the troop can be detected by observing displacement behavior, i.e. who causes others to ‘clear the deck’ upon approach. In our troop, Baraka is at the top, followed by Calaya, who quickly and dramatically established herself as the “queen gorilla” of the females. Mandara is next in line, and Kibibi follows behind her.
Zoo visitors who stay at the Great Ape House long enough have a good chance of seeing examples of displacement behavior in action. If the females are in one location and Baraka approaches, they may leave the immediate area. If Mandara and Kibibi are in a spot and Calaya approaches, the two may leave that area. Displacement behavior is more prevalent when there is some tension in the group.
From time to time, an interesting dynamic surfaces when Calaya is displaced by both Mandara and Kibibi. It is a rare occurrence, but it does happen. The Mandara and Kibibi alliance can be quite forceful. There have been times when they backed Baraka down!
Several years ago, Baraka and Mandara were engaged in an extremely intense encounter. Kibibi was much younger and smaller in size, and I was concerned that she may get caught in the fray. As the vocalizations and physical contact intensified, Mandara picked up Kibibi. Then, something quite spectacular happened. Mandra pushed Kibibi towards Baraka, and Kibibi started to bite Baraka’s ankles! He swatted her away several times, but she kept coming back.
When Baraka and Mandara settled their dispute, Kibbi continued to bite his ankles. He dismissed her attempts, and eventually she stopped. Watching Mandara teach Kibibi how to defend herself was fascinating. I will never forget it!
As Calaya becomes more comfortable with Moke exploring and interacting with the members of his troop, it will be interesting to watch his elders teach him how to be a gorilla.Can’t get enough of Moke? Visit him at the Smithsonian’s National Zoo’s Great Ape House from 9 a.m. to 6 p.m. Please note that the gorillas have the option to rest in an off-exhibit enclosure if they choose. Don’t miss the gorilla keeper chat, which takes place at 11:30 a.m. daily, to get the latest scoop on our troop.