What's Your Color?

Last spring, my husband put out short lengths of red and green yarn for nesting birds. Within 45 minutes, they'd taken all the red yarn, but left the green. We put out more red yarn, which the birds grabbed, but they still didn't touch the green. Can you tell us if birds can distinguish colors and why they might have left the green yarn?

—Bev LeCount, Elkhart, Indiana

George: Birds can see the same colors we can. That's why male birds usually are more colorful than females. Males are trying to attract mates, while females need to blend in with the habitat when incubating eggs and feeding young. However, it's difficult to answer why your birds chose the red yarn over green for nesting material. Perhaps the red blended better with their selected nesting habitat. Or, maybe the red color was meant to warn predators to stay away. Although we can't be sure of the exact reason, it definitely has something to do with survival.