Center for Animal Welfare, USDA APHIS Animal Care, Kansas City, MO 64131 USA
Captive bears may exhibit behavioral abnormalities. While some appear to adapt to captive situations, others may develop obvious behavioral issues or coping mechanisms. Studies indicate species of carnivore with the largest ranges and long travel distances are most likely to exhibit stereotypies in captivity.1 Bears generally have large ranges in their natural habitats and travel extensively to obtain food. Medical or dental problems, reproductive frustration, or boredom from a lack of stimulation may also lead to the development of stereotypic behaviors.2 Bears with stereotypies should receive physical examinations and appropriate veterinary medical workups to rule out chronic or painful conditions. A behavioral assessment also is essential.
Animal Welfare Regulations for Bears
All species of bears, except polar bears (Ursus maritimus), are covered in the Animal Welfare Regulations listed under Subpart F. Regulations specific to polar bears are included in Subpart E, marine mammals. Subpart F covers the humane handling, care, treatment, and transportation of warm-blooded animals other than dogs, cats, rabbits, hamsters, guinea pigs, nonhuman primates, and marine mammals. Housing regulations including ambient temperature, ventilation, lighting, drainage, shelter from sunlight and inclement weather, and space are addressed in Subpart F of the Animal Welfare Act Standards. Feeding, watering, sanitation, employees, separation, and all aspects of transportation are also covered in Subpart F. Regulations specific to polar bears are found in the Animal Welfare Regulations Subpart E, §3.104 (e). They state primary enclosures must have a pool of water, a dry resting and social interaction area, and a den. There must be enough shade to accommodate all polar bears housed in the primary enclosure at the same time. The den must be positioned so the viewing public will not be visible to the bears from the interior of the den.
The Animal Welfare Act regulations require sufficient space for each animal to make normal postural and social adjustments with adequate freedom of movement. Since this is a performance-based standard, a determination of compliance with this requirement is made by U.S. Department of Agriculture inspectors at the time of inspection, with the animal(s) present.
Providing adequate space for bears not only gives them more incentive to exercise but may help to prevent stereotypies from developing. Species of bears that maintain large territories in the wild, such as polar bears, as well as bears that naturally travel large distances daily to forage are more likely to develop pacing behaviors or other stereotypies.1 Vertical space is important for many species of bears, especially arboreal species such as the spectacled bears (Tremarctos ornatus), and climbing structures offer opportunities for the bears to perform all of their natural behaviors and may improve their daily activity levels. Bears may also be encouraged to explore and increase their daily activity when food incentives or other positive reinforcements are introduced into their environment. Training animals to move from one area to another promotes exercise and may help to prevent or extinguish repetitive behaviors. While polar bears must be provided large pools in which to swim, all bears benefit from having pools in their enclosures, and swimming should be considered one of their natural behaviors.
Substrate composition is an important consideration for bears. Housing them on natural substrates such as grass, dirt, or sand, or using wood or supple engineered floors is preferable to concrete. Strategically placing substrates that yield to weight in areas where bears spend time or pace may help to prevent arthritis or other injuries.
Many species of bears are omnivores and have nutritional requirements similar to domestic dogs. Some species of bears have specialized diets. Natural diets for most bears include a wide range of items including fish and insects to a variety of plant material. High-quality dog kibble may provide adequate nutrition when fed with other appropriate food items and could be scattered in enclosures as enrichment and to promote foraging behaviors. Commercial complete raw meat diets designed for carnivores also may be used to satisfy nutritional needs of bears. Previously frozen fish must be supplemented with vitamin E and thiamine. A recommended diet for bears includes about 50% balanced commercial product and 50% vegetables, greens, fruits, seeds, nuts, insects, meat and/or fish.3 Diets must be adjusted in response to seasonal changes in physiology and allow bears to feed to satiety during fall hyperphagia. Bears are efficient at storing energy and feeding diets with higher fat content such as kibble, meat, or fish may lead to obesity. Body weight and body condition should be monitored regularly. Fruit, grain, or all-meat diets (with no bones) that are not supplemented with calcium and appropriate vitamins will lead to crippling nutritional diseases. A calcium:phosphorus ratio imbalance may cause growth problems or metabolic bone disease. Bears maintained on optimal diets and provided with appropriate supplements will have fewer health and welfare issues. Obese bears may suffer with premature joint problems or other obesity-related medical problems.
In addition to essential enclosure furnishings that allow for normal social and postural adjustments, such as digging, denning, swimming and climbing, provision of enrichment items is a best practice. Enrichment is not mentioned in Subparts E or F of the USDA Regulations and Standards; however, institutions housing bears are encouraged to provide thoughtful enrichment to the bears. Enrichment may include species-specific elements in the enclosures such as toys, food puzzles, rotating new scents within the environment, and logs. Toys should be carefully chosen and indestructible. Plastic drums that float or are partially filled with water have been successful enrichment for polar bears. Sturdy plastic balls and plastic puzzle feeders designed for bears tend to make safe toys. All toys should be checked regularly to ensure integrity. Other enrichment may involve placing food frozen into blocks into the exhibit. One way to enhance the effect is by periodic rotation of enrichment items. Compatible cage mates also offer enrichment; however, incompatible pairings may result in stressful situations, fights, and even mortality. Training bears to perform simple behaviors may also be considered enrichment because it involves something different for the animals to do each day.
1. Club R, Mason GJ. Natural behavioural biology as a risk factor in carnivore welfare: how analysing species differences could help zoos improve enclosures. Appl Anim Behav Sci. 2007;102:303–328.
2. Maslak R, Sergiel A, Hill SP. Some aspects of locomotory stereotypies in spectacled bears (Tremarctos ornatus) and changes in behavior after relocation and dental treatment. J Vet Behav. 2013;8.5:335–341.
3. Morris C. Diet and nutrition for lions, tigers, and bears. Proc Lions Tigers Bears Symp [Internet]; 2014 [cited 2017 June 30]. Available from http://origin-qps.onstreammedia.com/origin/usda/%5BInbox%5D/DM/121515/DrCherylMorrisPresentationCAPSFINAL.wmv. (VIN editor: This link was not accessible as of 11-25-20.)