Q: At night, with an LED flashlight, what color are your eyes, Mr. Brown Bear? How about your cousin Mr. Black?—Rick Guidos, via email
A: Was that you shining a flashlight into my eyes the other night? If so, you’re in big trouble, Mister.
Like dogs, deer, wolves, foxes, cats, and scores of other animals, I’ve got a membrane in my eyes called a tapetum lucidum, which reflects light back toward my iris to improve night vision (sorry: humans don’t have them). When a bright light gets shined into them, they beam back out with a reflective glow.
In photos, the glow ranges from yellow to yellowish orange, though some people report seeing red or green. (Variations in color between species often come from the presence of nutrients like riboflavin, distortions in the lens, and iris color.) Black bears also appear yellow to orange, though people sometimes report seeing red.
Bottom line: You’re unlikely to identify my species at night solely by shining a light into my eyes.
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