Imagine this Black-capped Chickadee flying toward its nest, carrying fresh insects for its chicks. A moment later, it emerges with a tiny white pouch in its bill. The chickadee drops the object into the vegetation below. That outgoing payload is a fecal sac, a remarkable adaptation found in nesting songbirds. Nestlings — often within seconds of being fed by an adult — excrete waste in tidy little sacs. Then the dutiful parent switches tasks, from meal delivery to waste management.
Chickadees Clean up after the Youngsters
Written by Bob Sundstrom
This is BirdNote.
[Black-capped Chickadee calls http://macaulaylibrary.org/audio/98802 ]
An adult Black-capped Chickadee flies in toward its nest, carrying a beakful of fresh insects. Reaching a long-dead tree trunk, the bird disappears inside the nest cavity it’s excavated with its mate and delivers the goods to the impatient chicks within. [Black-capped Chickadee foraging calls http://macaulaylibrary.org/audio/51144 ]
A moment later, out pops the adult. But once again, it’s carrying something in its bill — what looks like a tiny white pouch. Still on the wing, the chickadee drops the object into the vegetation below.
That outgoing payload was a fecal sac, a remarkable adaptation found in nesting songbirds. Nestlings, often within seconds of begin fed by the adult, excrete waste in tidy little sacs with a gelatinous outer coating. The dutiful parent bird now switches tasks, from meal delivery to waste management. By dropping the sac a safe distance from the nest, the birds tidy the nest while discarding clues a predator might use to detect vulnerable nestlings. [Black-capped Chickadee calls, http://macaulaylibrary.org/audio/98802 ]
The fecal sac. For anyone who has ever changed a diaper, it’s a simple solution we can only marvel at.
For BirdNote, I’m Mary McCann.
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Black-capped Chickadee calls  recorded by G A Keller. Black-capped Chickadee forage sounds  recorded by K J Colver
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Executive Producer: Dominic Black
© 2015 Tune In to Nature.org July 2018 Narrator: Mary McCann
ID # chickadee-03-2015-07-10chickadee-03