Tool use in gorillas

Hello, everyone! I’m Courtney, a gorilla caregiver, here to tell you about some of the tool-use skills our gorillas have and how most of their enrichment opportunities encourage those natural behaviors.

Gorillas, like other apes, use sticks as tools to forage for food. Observing tool-use in animals is exciting, because it highlights similarities between humans and other members of the animal kingdom in terms of problem-solving skills and dexterity. These are some pretty intelligent creatures! It wasn’t until 2005 that a gorilla in the wild was observed using a stick as a tool to fish for ants, though long before that gorillas in zoological settings were often observed using tools to forage for food. Beyond foraging, there have also been a few scientific studies that found gorillas in the wild using sticks to determine the depth of water! So it is safe to say this animals have incredible minds.

Here at Zoo Atlanta, enrichment is a major part of our daily care for all our animals. We like to use enrichment that encourages their natural behaviors like foraging. Some of the enrichment that may require tools are: feeder plates, PVC tubes, and our newest addition, the termite mound. Feeder plates we can hide in their habitats. These are flat plates usually covered with oatmeal mixed with either some sunflower seeds or raisins that are secured within mesh boxes in their habitats. They can use their fingers to get the oatmeal off the plate or sometimes that can use small sticks to get the oatmeal. We like to mix up the flavors; that way it is not just plain oatmeal all the time. The gorillas like it that way too! For instance, with the PVC tubes, we normally fill them with Jell-O! The flavor of the Jell-O is most often cherry, but we mix in raisins, sunflower seeds, or some other yummy treats for them to enjoy. To get the Jell-O out of these tubes, though, they need to use sticks. Since the PVC tubes are normally mounted on the mesh in their bedrooms, we provide them with browse such as bamboo or willow which they can use to probe the Jell-O out of the tubes.

The newest enrichment item that most encourages their natural behaviors is the termite mound in Habitat 1! (It is a recreation, of course, so does not contain termites.) On the outside, the mound might just look like a big rock with holes in it, but it is actually an awesome form of enrichment and education! On the back side of the termite mound there is a door that we can open, and inside are several tubes with screw on caps. We can pick and choose whether to fill all the tubes with food or just a few or none of them. This keeps it interesting to the group of boys that spend time in that habitat. We can fill the tubes with raisins, grapes, oatmeal, applesauce, oats, Jell-O or whatever we choose to. Charlie, Kekla and Stadi are the big bachelors who live in habitat 1 and get to enjoy the termite mound! Charlie, the youngest of the group, is normally the one to interact with it and he loves finding out what’s inside! To make this enrichment a little more challenging, the boys may have to find their own stick in the habitat rather than have them given to them. They have to search for a proper stick and use it to see what is in the termite mound. This is exactly what gorillas would do in the wild. Termite mounds are everywhere in their natural habitats filled with yummy termites for them to eat. The termite mounds are a great expression of their tool-use skills!

Charlie, the youngest of these three adult bachelor gorillas, has an interesting way of expressing his tool-use skills. In their night areas, Charlie, Kekla and Stadi are what we might consider roommates, but they do have their own room. Charlie’s room is right next to Stadi’s, and there is a mesh wall between them so that they can see each other and communicate with each other. Charlie, being the intelligent gorilla he is, will sometimes use his tool-use skills to try to steal Stadi’s food. As you can imagine, Stadi is not a big fan of this particular expression of Charlie’s tool-use!

So, next time you’re at the Zoo, watch the gorillas a little closer and see if you notice any of their tool-use skills! Who knows? Maybe Charlie will find something good in the termite mound!
Courtney Meyer
Seasonal Keeper, Primates