Rock Pigeons. Photo: Paul Farnfield/Alamy

This audio story is brought to you by BirdNote, a partner of the National Audubon Society. BirdNote episodes air daily on public radio stations nationwide.

Transcript:

This is BirdNote.

Birds lay eggs. That means they don’t nurse their young… right? Well, have you ever heard of something called “pigeon milk?”

Pigeons, one of the most ancient of domesticated birds, feed their nestlings a peculiar, milky liquid—straight from the adult’s beak to the baby’s throat.

It’s often called “crop milk,” because it comes from special cells in the bird’s crop. The crop is a section of the lower esophagus in some birds that is used for storing food before digestion.

Unlike milk from mammals, pigeon milk doesn’t come from a mammary gland. But it does come loaded with antioxidants and immune boosters that help the new hatchlings survive.

A couple of days before their eggs hatch, both pigeon parents start making the milky substance, which they’ll feed their hatchlings over the first ten days of their lives. When the special feeding stops, the special crop milk cells return to normal.

Pigeons and doves aren’t the only birds that can make this special milk. Flamingos and some species of penguins can, too.

For BirdNote, I’m Michael Stein.

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Credits:

Written by Bob Sundstrom

Producer: John Kessler

Managing Producer: Jason Saul

Associate Producer: Ellen Blackstone

Editor: Ashley Ahearn

Narrator: Michael Stein

Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Recorded by ML 69278 A Priori.

BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.

© 2019 Tune In to Nature.org March 2019