Behavioral enrichment is an animal husbandry principle that seeks to enhance the quality of captive animal care by identifying and providing the environmental stimuli necessary for optimal psychological and physiological well-being. Enrichment can either be active or passive, depending on whether it requires direct contact between the animal and the enrichment. A variety of enrichment techniques are used to create desired outcomes similar to an animal's individual and species' history. Each of the techniques used is intended to stimulate the animal's senses similarly to how they would be activated in the wild. Provided enrichment may be seen in the form of auditory, olfactory, habitat factors, food, research projects, training, and objects.
Purpose
Environmental enrichment can improve the overall welfare of animals in captivity and create a habitat similar to what they would experience in their wild environment. It aims to maintain an animal's physical and psychological health by increasing the range or number of species-specific behaviors, increasing positive interaction with the captive environment, preventing or reducing the frequency of abnormal behaviors, such as stereotypies, and increasing the individual's ability to cope with the challenges of captivity. Stereotypies are seen in captive animals due to stress and boredom. This includes pacing, self-harm, over-grooming, head-weaving, etc.
Environmental enrichment can be offered to any animal in captivity, including: Animals in zoos and related facilities Animals in sanctuaries Animals in shelters and adoption centers Animals used for research Animals used for companionship, e.g. dogs, cats, rabbits, etc. Environmental enrichment can be beneficial to a wide range of vertebrates and invertebrates such as land mammals, marine mammals, and amphibians. In the United States, specific regulations (Animal Welfare Act of 1966) must be followed for enrichment plans in order to guarantee, regulate, and provide appropriate living environments and stimulation for animals in captivity. Moreover, the Association of Zoos and Aquariums (also known as the AZA), requires that animal husbandry and welfare be a main concern for those caring for animals in captivity.
Passive enrichment
Passive enrichment provides sensory stimulation but no direct contact or control. This type of enrichment is commonly used for its potential to benefit several animals simultaneously as well as requiring limited direct animal contact.
Visual enrichment
Visual enrichment is typically provided by changing the layout of an animal's holding area. The type of visual enrichment can vary, from something as simple as adding pictures on walls to videotapes and television. Visual enrichment such as television can especially benefit animals housed in single cages.
Mirrors are also a potential form of enrichment, specifically for animals that display an understanding of self-recognition, such as non-human primates. In addition to using mirrors to reflect the animal's own image, mirrors can also be angled so the animal is able to see normally out-of-sight areas of the holding area.
Enclosures in modern zoos are often designed to facilitate environmental enrichment. For example, the Denver Zoo's exhibit Predator Ridge allows different African carnivores to be rotated among several enclosures, providing the animals with a differently sized environment.
Auditory enrichment
In the wild, animals are exposed to a variety of sounds that they normally do not encounter in captivity. Auditory enrichment can be used to mimic the animal's natural habitat. Types of nature-based auditory enrichment include rain forest sounds and con-specific vocalizations.
The most common form of auditory enrichment is music, whose principal stems primarily from its benefit to humans. The benefits of classical music have been widely studied in animals, from sows to non-human primates. Studies have also looked at various other genres, such as pop and rock, but their ability to provide effective enrichment remains inconclusive. Most types of music that are selected for enrichment are based on human preferences, causing anthropomorphic biases that may not translate to other animals. Therefore, music that is specifically attuned to the animal's auditory senses could be beneficial. Species-specific sounds require further research to find what pitch, frequency, and range is most suitable for the animal.