Education:Stories from the Field
You will catch more bears with honey than vinegar
Of the eight species of bear, the American black bear Ursus americanus is the most numerous and one of only two bear species worldwide that are not either threatened or endangered. Using black bears as a study model can help researchers understand other bear species, such as the giant panda Ailuropoda melanoleuca. However, due to the intensive efforts of conservation researchers, more is currently known about the basic reproductive biology of the critically endangered giant panda than that of the more common black bear!
As a first step toward our goal of filling in the gaps, two animal behavior experts from the San Diego Zoo were asked to develop a training program for semi-free-ranging adult black bears. The idea was to collect urine samples in a noninvasive way from bears living in the Black Hills of South Dakota. Daily urine samples could give researchers information on the changing endocrine levels of mature female black bears through estrus during the June to July breeding season. But how to obtain such samples? With training, of course! Five female black bears were taught to associate urination with a positive reward, such as honey-sweetened water. By using training for noninvasive sampling rather than more conventional physical or chemical restraint methods, Dr. Tom Spady of the San Diego Zoo's CRES was able to collect urine samples without harming the bears in any way.
Dr. Spady will use the urine samples to monitor the daily changes in steroid hormone levels during the breeding season. This will help determine the start and length of estrus and ovulation, and will give us the most thorough and detailed characterization of the estrous cycle in any bear species other than the giant panda.
More
Fat Reserves and Reproduction in Black Bears
Contrasting Patterns of Maternal Care in the Giant Panda and American Black Bear
