Every species of animal requires enrichment that is adapted to their particular behavioral characteristics or personality. These characteristics can be identified by observation and research of species in the wild and in zoos.

Housing primates in appropriate social situations is one of the most significant ways to enrich their lives. Primates have active minds and complex social relationships, and companionship provides a constant source of stimulation.

Zoo animals also have individual personalities and abilities. Whether a primate is interacting with its enclosure, a toy/food stimulus, or is sleeping, there are many ways that the lives of these animals can be enriched. Because there is curiosity about the cognitive abilities of gorillas and orangutans participate in a number of ongoing research projects, which also offer mental stimulation.

At the National Zoo, enrichment items are approved through the exhibit curator and veterinarian and nutritionist. The Primate Program provides enrichment to all of the species in the unit. There are many types of enrichment available. Some are tried and true, and some the result of creative keepers.

Enrichment items include: burlap bags, craft paper, cardboard boxes, treat tubes, sheets, hard rubber toys, forage foods such as popcorn, and browse. Enrichment varies by species, as follows.

Gibbons

Each family group is rotated through the enclosures on a four-day cycle. They each spend two days with access to the outside followed by two days inside.

They are given frozen fruit popsicles, mealworms and crickets. They also receive browse, which they seem to enjoy playing with more than eating. One of their favorite snacks is mulberry browse with the berries.

Gorillas and Orangutans

Treat Tubes
Treat tubes are filled with various liquid foods such as rice cereal, oatmeal, peanut butter, honey, low-sugar syrup, mustard, and other low-sugar, low-fat, and low-salt foods. Metal treat tubes are attached to perforated panels on the enclosure mesh; bamboo treat tubes are left around the enclosures. The animals use hay or browse to fish the food out of the tubes.

Browse
The animals are given branches daily. They strip and eat the leaves and bark, and sometimes the woody portions. The branches come from local trees; bamboo is also provided. Gorillas and orangutans use branches for social displays and as tools.

Hay
The animals are provided with hay to use for nest building and for staff to hide food to encourage foraging.

Foraging
Keepers scatter foraging food around the cages and yards for the animals, and the animals search for the food as they would in the wild. Foraging foods include air-popped popcorn, walnuts, peanuts, Bird of Paradise pellets, herbivore pellets, low-fat dog food, and dry cereal.

Research
Orangutans are participating in two research projects with Karyl Swartz and the Language Project with Rob Shumaker at Think Tank.

Play Equipment
The cages are equipped with different types of equipment to play on or with. The idea is to keep animals active and interested in their surroundings and, whenever possible, give them choices of things to do.

Play equipment includes:

  • Ropes
  • Hercules bones
  • Large, plastic toys or shapes
  • Fire hoses
  • Pressed rawhide bones
  • Swivel stool
  • Indestructible balls
  • Rotten wood
  • Sheets/shirts
  • Burlap
  • Rubber tubs
  • Paper
  • Cardboard (orangutans only; gorillas eat it)

Lemurs

Most of the enrichment is food oriented. Browse and fruits are scattered around the island to simulate natural foraging behavior.

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