Primate Enrichment at PASA Wildlife Centers

Get a glimpse of how PASA members use enrichment to improve the quality of life for the primates in their care.

by Alexandra Reddy

Pan African Sanctuary Alliance members have rescued many chimpanzees, gorillas and monkeys from devastating situations. In 2019 alone, the Alliance rescued over 300 primates from cruelty and reintroduced 195 primates back to the wild. Many of these animals were orphaned by bushmeat hunters, kept illegally as pets, or smuggled outside of Africa. They have endured a great deal of trauma.

For as much abuse as some humans have inflicted upon these animals – many of which are endangered or critically endangered – there are countless numbers of champions working to brighten their lives.

Ideally, these rescued animals can be reintroduced to the wild, but this is not always an option. 7 to 10 years are often required to gain the many skills essential for living in harsh forest conditions, and even that may not be enough time for primates that were torn from the forest in early life. (Read more about a recent reintroduction by PASA-member Ape Action Africa in Cameroon here.) When animals cannot be reintroduced, the wildlife centers’ expert staff are prepared to provide lifelong care.

This commitment to care includes: proper nutrition, specialized veterinary care and something equally important: enrichment!

Climbing structure at PASA-member Sweetwaters Chimpanzee Sanctuary in Kenya.

What is Enrichment?
Enrichment is anything that encourages an animals´ natural behaviors and improves their quality of life. Enrichment can include group living inanimate objects, habitat additions and more. Enrichment gives animals the opportunity to exercise choice, and allows them to control their environment while engaging in healthy, species-typical behaviors. Enrichment can come in all shapes and sizes and ultimately benefits an animals´ psychological well-being. Below are several examples of enrichment from PASA-member sanctuaries.

Sweetwaters Chimpanzee Sanctuary offers tires and climbing structures as enrichment.

Social Enrichment As social animals, one of the best forms of enrichment for most primates is interaction with other individuals. Different species have unique social bonds. Experienced caregivers take time to reflect on the natural history of animals in their care in order to provide proper enrichment based on the unique needs and social dynamics of the species. Staff may often need to make determinations of the most optimal housing needs for primates in order to promote healthy relationships, but also recognize primates´ abilities to self-regulate within their groups. Gorillas, for instance, live in troops which typically include a full-grown adult male, known as a silverback, several adult females, their offspring, and black back males who have not yet fully matured. Gorillas communicate with each other in a myriad of ways: from vocalized grunts, whimpers and chuckles to expressive gestures of chest beats, claps and postures. Their social relationships are complex and can last a lifetime. Chimpanzees live in fission-fusion social groups where individuals form temporary small subgroups whose members belong to a larger community that can include over 100 individuals. Group composition and size changes regularly, and social bonds are strengthened and may in fact fluctuate by large amounts of social grooming and high-energy encounters that may include chasing and screaming. Chimpanzees have a unique hierarchy system. Without a doubt, social interaction is the most beneficial form of enrichment for group-living primates. From grooming, to tickling and playing games of chase, primates form life-long bonds with each other as well as with their dedicated caregivers.

Chimpanzees at Sweetwaters Chimpanzee Sanctuary catch their breakfast of papaya, oranges and bananas. (Photo by Adriane Ohanesian.)

Habitat Enrichment Environment can be enriched in many ways to encourage natural behaviors. For example, providing habitat additions such as varied substrate like wood chips, grass etc. can encourage foraging. Additionally, bedding, vines or climbing rope can help fuel natural behaviors. For example, both chimpanzees and gorillas will make nests at various times throughout the day and night. Chimpanzees will bend branches of trees and gorillas will pat down layers of leaves on the ground to create a cozy resting spots. Providing blankets, sheets or other cozy material can offer functional options for these nests, and apes can get very creative! Tall perching and climbing structures can allow animals to get an elevated view of the world around them. This enrichment adds novelty and complexity to the animals’ lives.

Chimpanzee Natasha with her newborn baby prepares a nest furnished with blankets, hay and leaves at Ngamba Island Sanctuary, a PASA-member in Uganda.

Edible Enrichment The most common type of enrichment is food-related. Caregivers present food in unique and stimulating ways that allow primates to use natural behaviors. Food can be smeared, scattered and hidden. Opportunities for foraging are common. Various plant cuttings (“browse”) are often disseminated as enrichment. To keep things interesting, edible enrichment can be fed at random intervals with food of varied quantity, texture and freshness. The plant cuttings provided to these sanctuary-housed primates reflect their natural diet. Gorillas, for instance, are primarily folivores who eat leaves and shoots as well as nearly 100 other different plant species. Chimpanzees have an omnivorous diet of fruits, seeds, nuts, leaves, flowers and insects. Knowledge of these natural diets are incorporated into care at PASA-member sanctuaries throughout Africa.

Left: Chimpanzee Zachary, at PASA-member Sanaga-Yong Chimpanzee Rescue in Cameroon’s remote Mbargue Forest, is excited to receive his peanuts. Right: The team at Lola ya Bonobo prepares popcorn to be foraged.

Cognitive Enrichment and Toys Challenges such as puzzle feeders, balls, barrels and more can motivate and challenge animals. Durable enrichment toys allow primates to use their dexterous, strong fingers as they work to extract preferred treats. Frequently, these novel objects will be coated or filled with food-related enrichment, to make them extra-interesting. Many primates are known to recognize themselves in a mirror, which is another excellent form of cognitive enrichment. Primates, especially great apes, are highly intelligent problem-solvers. Providing them with opportunities to use their prowess and intellect to extract food, contemplate their individuality or employ ingenuity helps them use their species-specific behaviors. Enrichment does not necessarily need to be expensive. Just as human children might find a cardboard box more interesting than the actual toy that came in it, primates can be engaged with the most basic of items, particularly if it is something novel – and bonus points if it includes something edible! Creativity from caregivers and thoughtful input from volunteers throughout PASA-member wildlife centers has yielded numerous inspired enrichment items.

Left: PASA-member Lwiro Primate Rehabilitation Center in DRC provides pieces of hose pipe loaded with jam and sweet treats inside. Chimpanzees will reach their fingers in or use a stick as a tool to retrieve the healthy snack. Right: A young chimpanzee at PASA-member J.A.C.K. Chimpanzee Sanctuary explores a bucket.

Creating Enrichment: Teamwork & Creativity
Enrichment typically requires a fair amount of preparation before it can be given to animals. For great apes, it is beneficial to use reusable, durable items that can withstand the strength of these powerful animals. This means that lengthy construction and labor are often required. At the Ngamba Island Chimpanzee Sanctuary, 400 students from local school wildlife clubs learned the benefits that enrichment brings to animals first hand. These students worked alongside staff members to help construct balls, tire climbers, noise makers and feeding puzzles for the chimpanzees at Ngamba Island.

Providing opportunities for enrichment to primates helps promote the animals’ behavioral health and overall well-being. These animals face major threats from humans such as habitat loss, poaching, human-ape conflicts and infectious diseases such as Ebola and now Covid-19. Fortunately, dedicated, knowledgeable and creative professionals at PASA´s member wildlife centers work tirelessly to enrich the lives of the primates in their care. Help support their incredible efforts by making a donation. Thank you!

Students and Staff at Ngamba Island Chimpanzee Sanctuary fill feeding puzzles with honey and peanut butter.