Wildlife Conservation Society Bronx Zoo, Bronx, NY
Animal enrichment provides a stimulating environment for captive animals in order for them to demonstrate their species-typical behavior, to allow them exercise control or choice over their environment, and to enhance their well-being. Enrichment includes the design of stimulating and naturalistic enclosures and the introduction of stimuli in the animal’s environment. No matter how naturalistic a habitat, the animals need new stimuli, new opportunities and new challenges in their environment Great advances have been made since the first zoos opened, whose function was to display animals in cages to provide entertainment for the visitors. The modern zoo is concerned with the animal’s well being and with educating the visitors. Visitors enjoy seeing content, healthy and active animals. It is hoped that the captive wild species will act as ambassadors and encourage the visitors to understand the nature of the animals and participate in conservation programs.
There are five categories of enrichment, and there is some overlap between these areas. Habitat enrichment includes the natural and fabricated elements that are specifically designed and built into the exhibit, for the animal’s health, comfort and pleasure. At Tiger Mountain a pool has been provided for tigers to swim, and a sprinkler that is activated by the tiger to cool off. There are artificial rocks that provide heating or cooling.
Social enrichment is the management of each species in appropriate social groupings similar to life in the wild, which can include same or mixed species groupings. Young animals develop hunting skills as they chase, wrestle, swat and stalk each other. Their actions are similar to the way adults bring down their prey. Tigers and keepers have developed strong bonds as a result of their frequent daily interactions. The keepers demonstrate their interaction with the tigers to the general public three times a day.
Foraging enrichment encourages hunting and foraging behavior and extends feeding periods. The Tiger Mountain keepers hide and/or creatively present a portion of food each day. The keepers provide hidden treats and also place fish in blocks of ice. The tigers claw at and lick the ice until they get the treat at the center. Tigers have also been provided with a spinner from which they are able to release treats from the opening.
Novel object enrichment avoids predictability and boredom. The key is to surprise the animals by adding variety and variability. The keepers introduce various objects and activities into the exhibit to keep the animal’s interest and energy level high. Part of the enrichment is the searching and hunting before they are rewarded with a new object or smell or food. Working for the novel item keeps them stimulated. The keepers have provided the tigers with large balls and tires. Animal hides are dragged around by the tigers much in the same way that tigers in the wild would carry around their prey. Each day the keepers spread around a variety of scents, to keep the tiger noses active. After careful study, the keepers have found that the cheetahs have a preference for CK cologne, probably as it has musk as an ingredient.
Training is a formal process of learning and communication between animals and their caretakers. It is necessary for animal management, for shifting from one area to another. Training can help lessen the stress of a vet’s visit, as the keepers work with the tigers to establish behaviors needed during medical exams. Choice is part of training, positive reinforcement is used and there is no punishment or deprivation.
Two of the newest exhibits at the Bronx Zoo are excellent examples of how exhibit design enhances the well being of the animals in its care. The Congo Gorilla Forest opened in 1999 and there are many examples of how the exhibit design and the work of the keepers enrich the animals. The Congo exhibit is an interactive environment. The gorillas live in a simulated rain forest with their natural structure. There are two groups of gorillas that live within the building.
The other new exhibit Tiger Mountain opened in May 2003. The exhibit brings together all three elements of the WCS mission: making a strong connection between scientific and field conservation work; the optimal care and display of animals in zoos as ambassadors; and the creation of instructional programs that enliven the life sciences and increase our understanding and appreciation for wildlife.
A very popular activity is the training sessions that the keepers do at the sea lion pool. The training sessions provide interaction between the keepers and the sea lions that is stimulating and rewarding.
An exhibit called “Taking Care of Mind and Body Enriching Animals’ Lives” opened in Zoo Center. The displays show items that the keepers use to enrich the animals’ lives. There are balls that the tigers and bears have chewed upon.
The Friends of the Zoo, the docent organization at the Bronx Zoo, has assisted in preparing treats for many of the animals. The weekend docents created behavioral enrichment toys for the animals in the Education Department Handling Collection. This involves wrapping nuts in newspaper and then placing them in cardboard tubes. Also covering a nut with peanut butter and then rolling it in birdseed. Weekday docents have created piñatas using whole-wheat flour and plain newsprint paper. The piñata recipe was approved by the animal nutrition department. The piñatas are then filled with fruits and vegetables and given to the capuchin monkeys .
The famous Rockefeller Christmas tree was crafted into enrichment items for many of the zoo’s animals. The grizzlies were treated to edible treats attached to the top portion of the tree to encourage the bears to climb and forage for food. The snow leopards, lions and tigers had rabbit meat buried in holes made into a “slice” of the tree. The small-clawed otters found fresh fish hidden in branches of the tree.
To summarize, the mission of WCS is to provide more comfort for the zoo animals and the people who come to visit them. The goals of animal enrichment can be summarized as follows:
· To elicit natural behavior
· Provide the animals with choice and control over their environment
· Stimulate play, exploration and problem solving
· Provide opportunities for supplemental foraging
· Reduce stress during routine husbandry and veterinary procedures.