Summer Science Research Project

The Effects of Enrichment on A selected Captive Tiger
By: Alyssa Blake

All animal species require psychological, physical, and emotional stimulus in order to maintain a healthy way of life, especially wild animals in captivity. In places such as zoos and sanctuaries, enrichment programs are especially important in maintaining a healthy environment. The stimulation these programs provide have been widely studied and continuously proven to reduce the possibilities of abnormal, aggressive behaviors and provide an enriching environment. If a captive animal’s needs are not met and instead animals are provided with only a monotonous routine, the animals may develop certain negative characteristics and behavioral changes and negatively impact their health. One such stereotypical behavior that is affected is pacing, especially in large cats, such as tigers (Panthera tigris). The negative effects of captivity have been widely acknowledged in the literature and there is a general consensus that the limitations of a captive environment can lead to the performance of stereotypic behaviour in many species. There are several different types of enrichment including, food, sensory, and physical. Each of these types of enrichment is a way for the animals to have new experiences and increase their well being while in captivity. While working at the Wild Animal Sanctuary in Texas, I implemented an enrichment program of different activities for each day of the week. The overall results of most of the activities were positive, showing active, playful engagement with the enrichment items.

Background

The International Exotic Animal Sanctuary in Boyd Texas is the first sanctuary to ever be certified by the association of zoos and aquariums which is only accredited to fewer than 10% of the approximately 2,800 animal exhibitors licensed by the United States Department of Agriculture are AZA accredited! The sanctuary, now named the Wild Animal Sanctuary-Texas, has 41 acres of forested land to provide natural enclosures and habitats for our rescued animals. Their goal is all about saving animals from poor backgrounds. They have rescued captive exotic and endangered large carnivores that have been abused, abandoned, exploited or illegally kept and given them a home where they can live the rest of their lives in peace. 

 As many as 25,000 captive great cats, bears, wolves and other large carnivores are living in substandard conditions throughout the U.S. In fact, after illegal drugs and weapons, the exotic animal trade is the third largest source of illicit profits in America—and the world—today. 

There are hundreds of private facilities within the United States that breed and sell these species for profit. The United States Department of Agriculture (USDA) regulates only a handful of these facilities, as many do not have to be licensed if they are not exhibiting animals.  The US Fish and Wildlife Service (FWS) does not regulate these animals, as the vast majority are not considered true endangered species due to cross breeding and the lack of documentation that proves lineage. This captive wildlife issue began 40+ years ago in the United States, and has now begun to be a global issue - especially in other countries that have developing economies.  World-wide there are more than 100,000 animals like these that are being exploited in countless ways and our network of sanctuaries works to save hundreds of these animals each year.

Enrichment- What Was Done and Why?

Throughout the internship, the keepers explained how enrichment projects are done to maintain the animal’s well being and provide them with objects to keep them occupied or to play with whenever the mood strikes. As these animals do not live in the wild, stimulation provided by these enrichment objects is important in maintaining a healthy, happy animal.  Previously, studies have focussed on how enrichment efforts have stimulated natural behaviours and attempted to replicate certain behaviors that animals would typically exhibit in the wild. Stimulation was achieved through the provision of novel food items, changes to feeding routines and food provision, as well as novel toys/objects to stimulate hunting behaviours. Studies have used feeding boxes and explored their effects as well as  cardboard box animals; burlap sacks hung from trees that move when “attacked”; ropes for tugging (a ‘tiger-tug’); watermelons that roll away when chased; and frozen blood balls. Additionally, scents, such as spices, can encourage these natural communicatory and territorial behaviours (such as patrolling and spraying) and increase stimulation (Szokalski, 2012). Boredom, in captive situations, may be alleviated by adding novel stimuli, such as odors, to the enclosure. Tigers exhibited the highest increases in active behaviors with the addition of spices to their enclosures (Skibiel, 2007). For this study, a  weekly enrichment program was created for a chosen animal (and later the enrichment used during the project was provided to other animals in the facility) to determine that animal’s preferences and reactions to different enrichment activities. For the tiger, Saber, I chose adding bubbles to his pool, a box with lemongrass scent, an ice pop with steak, a box with a blood pop, catnip on his platform, and adding a tire swing to his enclosure. I examined his behaviors with each stimulus based on observations from similar enrichment studies. Most of the enrichment items were actively engaged with and showed positive results. However, the catnip spread on one of his platforms proved uninteresting to Saber and was ignored completely. The bubble bath, while thoroughly inspected and pawed at curiously, was also ignored after his initial inspection. The tire swing, however, was continuously inspected and cautiously swatted at several times. While Saber was first nervous about the swing, he later destroyed the tire so much that it later had to be removed. Lastly, both enrichment ideas that included boxes or treats were actively and continuously engaged with until the food was eaten and the boxes completely shredded in his pool.

Citations:

Skibiel, A. L., Trevino, H. S., & Naugher, K. (2007). Comparison of several types of enrichment for captive felids. Zoo Biology: Published in affiliation with the American Zoo and Aquarium Association, 26(5), 371-381.)

Szokalski, M. S., Litchfield, C. A., & Foster, W. K. (2012). Enrichment for captive tigers (Panthera tigris): Current knowledge and future directions. Applied Animal Behaviour Science, 139(1-2), 1-9.