Answer: It's called "countershading." Countershading tends to eliminate a sharply defined shadow or silhouette, making the birds more inconspicuous to possible predators. Above, where light is the brightest, a darker color absorbs the most light. Below, where the light is dimmest, a lighter color reflects the most light.
Eastern Phoebe, above; Chipping Sparrow, near right; Blue-gray Gnatcatcher, far right top; Red-eyed Vireo, far right bottom. |
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Question: Why do so many birds have
darker colors on the top and lighter colors below?
Most
small woodland birds and shorebirds are countershaded.