This story comes to you through a partnership between Audubon and BirdNote, a show that airs daily on public radio stations nationwide.
Written by Gordon Orians
For birds and other animals with good natural insulation, winter provides a striking benefit as they scavenge. Bacteria function very slowly or not at all in the cold, preventing dead bodies from rotting in sub-freezing temperatures.
By way of contrast, in tropical Africa when an animal dies, bacteria quickly attack the body and convert it to a smelly, toxic mess unsuitable as food for most organisms. Vultures patrol the savanna skies, using their excellent sense of smell to find carcasses before bacteria render them inedible.
But in northern latitudes, ravens and other scavenging birds and animals take advantage of winter’s cold storage. When a caribou, moose, or deer dies in Canada, Alaska, or other cold place in the winter, it’s available to be eaten for months and months. Bacteria must wait until spring warms the carcass before they can begin to consume it.
That’s why ravens can survive during the winter in the far north. That’s why wolverines are in much better shape in the winter than they are in summer. Ravens, magpies, wolverines, wolves and foxes can rely on carcasses during the winter, because the microorganisms are suppressed by the cold.
For BirdNote, I’m Michael Stein.
Sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Call of the Raven recorded by G. Vyn; Howls of Gray Wolves recorded by W.W.H. Gunn.
Producer: John Kessler
Executive Producer: Chris Peterson
© 2013 Tune In to Nature.org December 2013 Narrator: Michael Stein