Every year, many people ask: “I have a bald bird at my feeder! Is it sick? What should I do?”
Often, these bald birds are Blue Jays or Northern Cardinals. Maybe the fact that these birds are so brightly colored and normally have tall crests on their heads may make them seem EXTRA weird, but by any standards, these bald birds are pretty bizarre-looking. Thankfully, most of these birds aren’t sick—they’re just molting!
Molting is a normal process for birds, but for reasons no one is quite sure of yet, sometimes birds molt in a very abnormal way. In late summer and fall, when birds typically molt, they usually lose and replace their feathers gradually. Some feathers fall out here and there and are then replaced by new ones that grow in—which makes sense. Better to have somewhat sparser feathers than to have a big old bald spot. Occasionally, however, a bird loses all of the feathers on its head at the same time, resulting in oddly bald-headed birds. This is particularly true of Blue Jays, which molt the feather of the head, or “capital tract,” all at once. New head feathers usually grow in after about a week, and the bird goes back to looking like just a normal bird.
Feathers, like human hair and nails, are nonliving structures. Molting is the way in which birds replace old and potentially damaged feathers, since they are ‘dead’ and can’t repair themselves. Most birds have only one full molt per year, but some species, such as the Marsh Wren, whose feathers go through more wear-and-tear than those of the average bird, molt twice a year. Some birds molt not only to maintain a functional set of feathers, but also to attain special feathers for the breeding season. Birds such as male Scarlet Tanagers undergo this “prenuptial” molt, transforming their dull olive-yellow plumage into spectacular bright red plumage.
Want to read more, and see some very strange photos? Visit this site from the Cornell Lab’s Project FeederWatch. One neat thing to notice in the photos: what a bird’s ear looks like! Can you find the Cardinal ear in the photo above?
Meanwhile, keep your eyes out for bald birds, and don’t worry, they’ll be “normal” soon!