Aug 23 2013
Have you noticed that a lot of birds are molting now? On the extreme side I’ve seen a bald male cardinal and Mary DeVaughn reported a bald blue jay, both of whom shed all their head feathers at once.
Less extreme-looking but still ragged are the house sparrows. Ten or more of them line up at my bird bath to splash wildly and loosen their old feathers.
Birds must molt to replace worn feathers but house sparrows, who don’t migrate in North America, have an additional reason. In August they put on heavier plumage that will keep them warm over the winter.
According to Ornithology by Frank B. Gill, the plumage on house sparrows weighs 0.9 grams in August. By the end of September they’re wearing 1.5 grams of feathers.
Our house sparrows are bulking up.
(credits: photo from Wikimedia Commons. Click on the image to see the original. Today’s Tenth Page is inspired by page 154 of Ornithology by Frank B. Gill.)