Bald Eagles (Haliaeetus leucocephalus) breed in the north. When winter comes, most migrate but some don’t go far and some simply head for the nearest coast. Eagles typically migrate by riding thermals: they find a column of warm rising air and let it carry them high into the sky; then they glide down to the bottom of another thermal and rise again. This allows the bird to travel without using much energy. Updrafts of air typically found along mountain ranges make them favored migration routes for eagles.
Why Do Bald Eagles Migrate?
It’s not cold weather that makes Bald Eagles move—they can tolerate winter temperatures—it’s ice that covers bodies of water and prevents the birds from fishing. Food is not as easy to find in winter.
Bald Eagles fish, hunt small animals, and eat carrion (dead animals), so in the winter they move to open water—sea coasts, rivers, dams, power plants, etc.—and to places with abundant animal life .
Where to Look for Bald Eagles in Winter
Winter is the best time to look for Bald Eagles because they tend to be concentrated in small areas. The number of Bald Eagles in one location can be truly astonishing: they are not only an impressive natural sight, but also an encouraging reminder of how the species has recovered from near extinction. This makes eagle viewing a popular winter activity for many North Americans.
Look for Bald Eagles where the fishing is good. The best time to see them fishing is in the morning, while in the afternoon you may find them resting in trees if they are not off hunting for other prey. There are a number of locations in North America particularly noted for large numbers of wintering eagles:
- The Chilkat River in Haines, Alaska hosts the most wintering Bald Eagles, with up to four thousand birds gathering along a four mile stretch of the river from October through February. The birds feast on salmon that have spawned and died.
- The Squamish River and other rivers of southern British Columbia attract about the same number of Bald Eagles as the Chilkat. Eagle watching is centered in Brackendale, British Columbia. December and January are the best months to see them.
- The Mississippi Valley also attracts many Bald Eagles during winter. They fish in the river and hunt small animals and other birds. The northern Mississippi provides the best viewing; by February, the birds are moving north again.
- On the east coast, the Annapolis Valley in Nova Scotia attracts Bald Eagles with its poultry farms. Poultry producers there deliberately throw dead chickens out into the fields for eagles to eat and hundreds of birds now winter in the valley. Sheffield Mills lies in the heart of eagle watching territory from November through March, with January and February being the best times.
Where Do Bald Eagles Sleep in Winter?
Though they’re fishing or hunting independently during the day, Bald Eagles roost together, sometimes in groups of several hundred birds. They begin gathering at the roost, often a large sheltered tree some distance from their feeding grounds, a couple of hours before sunset, and leave the next morning before sunrise.
Although gatherings of eagles are an impressive sight, it’s important that people not disturb them while they’re roosting or resting: if they take flight, they’ll use up precious reserves of energy that they need to survive until they can hunt again.
Sources:
American Bald Eagle Information.
"Bird Fact Sheets: Bald Eagle." Hinterland Who’s Who. (hww.ca)
“The Eagle Has Landed.” McClelland, Rosemary. 50Plus Feb 2003: 40-43.
 |
 |
