Grizzly Bear (Ursus arctos) Diet Management: Seasonal Diets to Attain Healthy Weight


Kerr K, O’Connor H, Shanks J, Thomas G, Hamlin C. 2017. Grizzly Bear (Ursus arctos) Diet Management: Seasonal Diets to Attain Healthy Weight. In Ward A, Coslik A, Brooks M Eds. Proceedings of the Twelfth Conference on Zoo and Wildlife Nutrition, Zoo and Wildlife Nutrition Foundation and AZA Nutrition Advisory Group, Frisco, TX.


Grizzly bears (Ursus Arctos) are specially adapted to survive the changing seasons of northern latitudes through changes in metabolism and behavior: In the zoo environment, these adaptations make weight management a challenge (Watts, 2009). Wild bears pack on the pounds during warm months to ensure they can survive the winter’s harsh weather and scarcity of food – losing as much as one-third of their body weight during hibernation (Robbins et al., 2005; Kingsley et al., 1983). At San Diego Zoo, the grizzly bears still pack on the pounds in warm months, but their winter isn’t so harsh, and in the past, food has been plentiful, resulting in bears that were overweight all year round. In January 2016, Nutritional Services and Animal Care Staff at San Diego Zoo partnered to develop a year-long diet plan that included seasonal shifts in when food energy is offered to bears and selection of dietary items with lower caloric density. Our goal was to encourage more appropriate seasonal fluctuations in body condition and body weight. Given their unique biology, success of the program could not be assessed until 1 year later: Through caloric restriction in the winter and spring of 2016 and 2017, we were able to attain seasonal changes in body weight of approximately 40 kg (15% of BW; double previous years). Efforts have continued in 2017 with a refined process and hopes for further success in weight management tailored to these seasonal animals.

[Kerr] 2017 – Grizzly bear diet management – seasonal diets to attain healthy weight.pdf     756 KB