Aug 23 2013

House Sparrows Bulk Up

Published by at 7:20 am under Bird Anatomy,Tenth Page

House sparrow molting, Sept 2008 (photo by Remi Jouan via Wikimedia Commons)

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.)

3 responses so far

3 Responses to “House Sparrows Bulk Up”

  1. Mary Ann Pikeon 23 Aug 2013 at 8:58 am

    This morning as I was driving to work I saw our local turkey flock with a couple of the males displaying. Not only are they confused about when they should be courting, but you could tell their tail feathers were molting and the fans that they were presenting to the ladies were sorry looking indeed!

  2. Kat Walterson 23 Aug 2013 at 10:14 am

    Just the other day we noticed about 10 sparrows splashing away in my bird bath. I guess your post explains that! Thanks for being so timely and always teaching us!!!

  3. John P. Englishon 23 Aug 2013 at 5:35 pm

    The sparrows are have a grand time in the courtyard fountain here. A veritable symphony last night – splashing water, chirping sparrows, singing cicadas and train whistles.

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