Previously, bears were thought to have poor visionFew studies about bears - to which group giant pandas belong - have been made. "It has long been thought that bears have poor vision, perhaps, because they have such excellent senses of smell and hearing." said graduate researcher Angela Kelling from Georgia Institute of Technology for Conservation Behavior in the School of Psychology.
A new study effectuated by Kelling at Zoo Atlanta seems to indicate that giant panda bears could see in color. The two panda bears of the Atlanta Zoo were able to see color and to discriminate between colors and various nuances of gray. "My study shows that giant pandas have some sort of color vision", said Kelling. "Most likely, their vision is dichromatic, since that seems to be the trend for carnivores".
Some researchers supposed that bears must have some kind of color vision helping them in identifying edible plants from the inedible ones, but little evidence about this was found. Experiments on black bears found that bears could distinguish blue from gray and green from gray.
Kelling investigated whether giant pandas can tell the difference between colors and shades of gray. She tested each color separately against gray. Three PVC pipes were used in the experiments, two hanging under a piece of paper that contained one of the 18 shades of gray and one that contained a color - red, green or blue. Pushing the pipe under a color, the panda received a reward, pushing one of the pipes under a gray paper, the panda received nothing. The pandas' capacity to distinguish green was variable, but mostly above chance. For red, both bears performed above chance every single time. Only one bear was healthy in order to complete the blue versus green tests. The other had a tooth problem that prevented him from eating the treats used as reinforcement. "While this study shows that giant pandas have some color vision, it wasn't conclusive as to what level of color vision they have," said Kelling.
"From this study, we can't tell if the pandas can tell the difference between the colors themselves, like red from blue, or blue from green. But we can see that they can determine if something is gray or colored. That ability and the accompanying visual acuity could lead to the pandas being better able to forage for bamboo. For instance, to determine whether to head for a bamboo patch that is healthy and colorful as opposed to one that is brown and dying."