

Join BirdNote tomorrow, November 30th!
Illustrator David Sibley and actor H. Jon Benjamin will face off in the bird illustration battle of the century during BirdNote's Year-end Celebration and Auction!
Around this time of year, Common Mergansers cross the U.S.-Canadian border on their way to wintering grounds in the Lower 48. But how do they know when to go? Ducks are well insulated against frigid winter temperatures, but mergansers can find their fishy prey only by diving below the surface of open water. So they’re doing just fine, resting and feeding in southern Canada, until a thin veneer of ice forms on their lake, signaling the time has arrived to head south!
BirdNote®
Common Mergansers Pushed by the Ice
Written by Dennis Paulson
This is BirdNote.
[Common Merganser calls]
Around this time of year, Common Mergansers are flying south from Canada to wintering grounds in the Lower 48.
What dictates when they decide to go?
[Wintry sounds]
These ducks, like most birds, are well insulated against frigid winter temperatures. But they do have to find food, and they only can find their fishy prey by diving below the surface in open bodies of water.
So they're doing just fine, resting and feeding in southern Canada, until they wake up one November morning and a thin veneer of ice is forming on their lake. That ice is a sign of the times — and enough to let the ducks know, they should be heading south.
[Common Merganser calls, splashing]
This makes Common Mergansers and some other diving ducks among the last of the migrants to appear in the US in late fall. In years to come, if they start to arrive later, it may be a sign that changes in climate are shaping their migratory behavior.
[Wind and ducks calling]
I’m Mary McCann.
BirdNote's newsletter delivers the wonder and joy of birds directly to your inbox. Sign up for our newsletter at BirdNote dot org to get a weekly preview of our shows, stories, photos, and more.
###
Senior Producer: Mark Bramhill
Producer: Sam Johnson
Managing Producer: Jazzi Johnson
Managing Producer: Ariana Remmel
Content Director: Jonese Franklin
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Common Merganser [61562] recorded by W. W. H. Gunn
Ambient sounds 'Track 2 Wind Mod Soft' from Nature SFX, recorded by Gordon Hempton, QuietPlanet.com. BirdNote’s theme was composed and played by Nancy Rumbel and John Kessler.
© 2015 BirdNote November 2014/2017/2021/2024/2026
Narrator: Mary McCann
ID# COME-01-2014-11-04






