Waterfowl such as this Greater White-fronted Goose have long followed a predictable schedule, flying south in autumn after breeding in the north. But for some birds, climate change may be delaying fall migration. Beginning in 1979, scientists in northern Europe recorded migration dates of geese and ducks during a period of 30 years. The data revealed six species that delayed southward migration. The reasons are complex, but a general trend of delayed fall migration will make waterfowl conservation increasingly challenging.
Waterfowl Migration in Flux
Written by Bob Sundstrom
This is BirdNote.
[Greater White-fronted Goose flight calls]
October skies traditionally ring with the rhythmic voices of geese, migrating southward. [Greater White-fronted Goose flight calls]
Waterfowl have long followed a remarkably predictable schedule, flying south in autumn after breeding in the north.
But for many of these birds, ongoing climate change may be delaying fall migration. Beginning in 1979, scientists in northern Europe recorded migration dates of ducks and geese. Over 30 years, six species showed pronounced delays in their dates of flying south — some of up to a month. [Mallards taking flight]
Some waterfowl time their departure south to when lakes on which they feed begin to freeze. And with climate change, water temperature has warmed even faster than air temperature. So with later freezing dates, waterfowl can remain farther north later in the fall. Also, fewer birds are inclined to travel as far south as they once did.
Other factors affecting migration are complex and include day length, severe weather events, and whether feeding habitat is available along migration routes. But a general trend of delayed fall migration will make conservation efforts on behalf of water-fowl more and more challenging. [Greater White-fronted Goose flight calls]
For BirdNote, I'm Michael Stein.
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Itha-ca, New York. Greater White-fronted Goose 132105 recorded by Gerrit Vyn; Mallards taking flight 3429 recorded by A. A. Allen.
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 October 2014/2015 Narrator: Michael Stein
ID# climatechange-03-2014-10-19 climatechange-03
article on delayed migration in Europe - http://www.bbc.co.uk/nature/15783321
Long Point Observatory paper on dabbling ducks, climate change, and change in fall/winter migration patterns