This year, the veterinary staff at the Seneca Park Zoo was once again invited by the New York State Department of Environmental Conservation (DEC) to accompany them on seven black bear den surveys throughout the southern tier region of New York.
Black bears are not true hibernators. They instead go into a state of torpor, which means they have the ability to slow down their metabolism and live off the reserves they built up in the fall. A black bear can wake up during the winter and will emerge from the den occasionally. Female black bears will wake briefly during their torpor to give birth to one to four cubs. The new mom will then drift back into sleep while the cubs continue to nurse and grow. In March, her cubs are roughly two months old and can weigh on average three to five pounds.
The females are still asleep enough that they can be approached, hopefully, without detection. These females have all been fitted with radio collars. By tracking the signal specific to each bear, DEC staff can locate where the female is denning. They scout out the den and assess whether they can safely approach the bear for immobilization. Under the guidance and direction of the DEC, Zoo vet staff, members of the U.S. Fish and Wildlife Service, students from Finger Lakes Community College and Cornell University, as well as landowners work together to begin the process.
The female bear is immobilized by DEC staff and only after they have safely anesthetized her do the rest of us move in. Any cubs she has are removed from the den and placed in fleece bags to keep warm. Students will measure ear and hair length, weigh and sex each cub and give them each a microchip that will allow unique identification throughout their lifetime. The female is given an overall physical exam that includes blood draws and fecal exams. Zoo vet staff will check heart rate, respiratory rate, reflex responses and temperature at frequent intervals to monitor the depth of anesthesia. If not done during a previous survey, she will also receive a microchip. Her radio collar is removed and she is fitted with a new one. Once all assessments are complete, the female is returned to her den and the cubs are placed back by her side. She will spend the next several hours recovering.
The DEC uses these surveys to collect information on the overall health status of the black bear population. Healthy females with healthy cubs mean that the region is able to sustain multiple bears. As the population of black bears in New York State continues to grow and expand into new areas, it is our responsibility to learn as much as we can about these amazing animals. Living with black bears is something we will all encounter at one time or another. It has been a privilege to work closely with the DEC to expand our knowledge of black bears.
- Robin English, Veterinary Technician