Wednesday, December 31, 2008

Bear Vision

Bears can see almost as well as humans, they tend to be nearsighted but have good depth perception. They have a layer of tissue called the tapetum lucidum that lies behind the retina that reflects light and improves their night vision. All bears have round pupils except giant pandas which have slits. Polar bears have a transparent eyelid (nictitating membrane) to filter snow glare and help them see underwater.

Studies have shown that bears can see colors. In a study done with giant pandas at Zoo Atlanta, it was not determined whether they could differentiate between colors but they could tell the difference between colors and gray. Being able to see colors may help bears find and distinguish ripe foods like berries, or fresh bamboo in the case of giant pandas.

For year’s people thought bears were colorblind and could not see well but research is showing this is not the case. We still have so much to learn about bears, it will be interesting to see what new things we learn in the future.

Giant Panda color vision study
Black bear and polar bear color vision study

Wendy Gardner, GBOP field specialist