An online resource based on the award-winning nature guide

Pileated Woodpecker Parents Removing Fecal Sacs

7-4-19 fecal sac 1B0A1346Young birds defecate in little packages called fecal sacs. These structures serve several purposes, one being that having waste contained in a sac keeps the nest relatively clean. Often parents consume these sacs when their nestlings are small (when young the birds don’t completely digest the food they eat and fecal sacs may provide parents with a nutritional snack), but eventually the adults usually retrieve them and fly away from the nest before dropping them. (The young of some species of birds in open nests perch on the rim of the nest and defecate.) Two to five days before fledging, Pileated Woodpeckers stop removing their offsprings’ fecal sacs (perhaps as an incentive to depart the nest?).

Naturally Curious is supported by donations. If you choose to contribute, you may go to and click on the yellow “donate” button.

7 responses

  1. Alice Pratt

    Birds have interesting habits! Happy 4th! 🇺🇸

    July 4, 2019 at 8:17 am

  2. John Jose

    I was at a vernal pool in Hubbard Park, Montpelier, this morning and was watching winter wrens carry food to a nest hidden by an overhanging section of bank along the pool, and carry away fecal sacs.

    July 4, 2019 at 10:33 am

  3. Viola

    This series on the pileated has been so interesting, and the accompanying photographs are outdtanding. Kudos, Mary, and thanks as always!

    July 4, 2019 at 1:14 pm

  4. For several years a pair of house finches (purple finches??) nested in a forsythia wreath beside my entry door. It was fascinating to watch the “crown” of fecal sacs build up around the edge of the nest. Of course the porch floor beneath the nest got pretty messy, but I loved having the nest there. We no longer live in that place, and don’t have a wreath outside our entry door. I wonder if the finches came back this year, looking for that wreath.

    July 4, 2019 at 1:18 pm

  5. Maine naturalist

    Do the fecal sacs (and removal thereof) also decrease predation risk by reducing the amount of young-bird scent in the nest?

    July 7, 2019 at 4:03 pm

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s