Gorilla Enrichment

Gorilla Enrichment, Part 1


I find enrichment to be the most rewarding yet challenging aspect of my job as a zookeeper. It’s no secret how intelligent our gorillas are, and we strive to make every day interesting and fun for them. Gorillas get lots and lots of one-on-one time with their keepers. We train them every day, which I think is the best form of enrichment and mental stimulation. We highlighted some of our training in last week’s blog entry. In addition to training, we also like to provide environmental enrichment.
The way to a gorilla’s heart is through food. Our gorillas would love it if all of their enrichment was edible. Unfortunately for them, we need to keep an eye on their caloric intake, so that is just not possible. We do, however, always try to present their food in a fun or interesting way. Scattering sunflower seeds in the yard or freshly popped popcorn throughout their bedding is a great example of really simple enrichment.  Picking our food up piece by piece could prove pretty tedious for us, but for gorillas, it encourages foraging, a natural behavior.
Puzzle feeders are another fun way for us to present food to our gorillas in a challenging way. A classic puzzle feeder is made from a PVC pipe. We install a screw cap on one end, close up the other end, and drill holes of various sizes into the pipe. We then fill the PVC with something small and yummy, like raisins, and give them to the gorillas. The gorillas must then manipulate the puzzle feeder in order to obtain the reward. Some of our smarter gorillas will use sticks as tools in order to fish out the treat. These puzzle feeders provide hours of entertainment for our gorillas.
Kongs are another fun and easy toy to give to the gorillas.  Yup, the same Kongs that you give to your dogs at home—our gorillas love them too. We smear peanut butter inside the Kongs or drizzle honey inside and then hide them all around their exhibit. They'll spend hours licking out every last bit. When they're done with them, some of our gorillas will pop the whole Kong in their mouths and chew on them, almost like a piece of gum.
Food variety is also one way that we keep things interesting for our gorillas. I often joke that our gorillas eat better than I do. Every day, they are offered a different variety of produce, greens, chow, fruit and forage items. This way they aren't eating the same things all of the time and hopefully don't get bored with their meal selections.

In the summer, our gorillas are offered freshly cut browse every day. Different things like bamboo shoots, honey locust branches, and mimosa really make them happy. Our on-site nutritionist also does a great job of offering them seasonal treats, things like locally grown tomatoes, seasonal squash or watermelon. We also vary the way we present food to them. Some days we might dice or mince their produce, while other times they're given whole carrots or tomatoes. Even the fruit that we use for training can be handed out in chunks or blended into smoothies. Gorillas, for the record, love smoothies.

When it's hot outside, we like to make frozen treats for them. We make giant popsicles using five gallon buckets or smaller ice cube-sized ones as well. A big frozen treat does a great job lengthening the amount of time a gorilla spends eating. It can be hours before they consume the whole popsicle. We can also cook some of their produce like carrots or parsnips.  Occasionally, we'll even add in some spices like cinnamon or oregano, just to change things up a bit.

Did you know you can adopt a gorilla at the Zoo? Adopting a Philadelphiz Zoo animal helps us make sure our animals receive the best possible care. Check back next week for more on how we offer enrichment to our gorillas!

Samantha NestorBy Samantha Nestor, Primate Keeper