In the column “Since You Asked” in every issue of BirdWatching, Contributing Editor Julie Craves answers readers’ questions about birds and bird behavior. Here is a question from our January/February 2019 issue.
Q: Can a bird’s eyes change color?— Erica Cameron, Kansas City, Missouri
A: The yellow-eyed glare of a hawk, or even a grackle, reminds us that not all birds have dark-colored irises. Next time you see a dull-plumaged young grackle, take a look at the eye color: They are brown. Only months after hatching do they turn pale. The photo above illustrates the difference.
The eye color of many species changes as they age, often from gray or brown to red or yellow. For example, Brown Thrashers start out with gray eyes that turn yellow; White-throated Sparrows, Dark-eyed Juncos, Gray Catbirds, and several woodpeckers have gray-brown eyes that turn reddish brown. A number of raptors, like Red-tailed and Cooper’s Hawks, have yellow eyes that turn red as they become adults.