One of the most important duties that zookeepers have is to make sure that the animals in their care are engaging in “species-typical behavior.” This means that we want our animals to behave in the Zoo the same way they behave in nature. And, in nature, a good portion of a primate’s day is spent looking for food. Ripping up bark and leaves, searching for fruit, insects and gum exudates (a sap-like substance), as well as digging in the dirt for tubers or roots are all ways that primates can find food in the wild.
In the Zoo, primates do identical behaviors with their enrichment foods. We scatter sunflower seeds, peanuts or mixed nuts around their exhibit before releasing them from their night houses.
We take ketchup, mustard or relish and drizzle tiny bits of it in places where it will be a surprise when they find it. Sometimes a teaspoon of non-fat yogurt or low-fat peanut butter might be smeared on some branches here and there, to the delight of the monkeys who find it. All of these foods are spread out in unexpected places and found only after the primates have eaten their most nutritious foods of primate biscuits and leafy greens, which are served for breakfast.
Our Animal Nutrition department prepares all of these goodies, and also procures earthworms, waxworms, mealworms and crickets, all of which are part of a rounded primate diet. Although primates are mostly vegetarian, some will slurp up a nice fat earthworm without a moment of hesitation!