Tweets by @topbirdingtours
The Bald Eagle is one of the most opportunistic predators with one of the most varied diets of any raptor in the world. They prefer fish, but any small to medium-sized bird or mammal will do. They’re not picky at mealtimes.
By Rex Graham
The national symbol of the U.S. is almost always found close to water. It expertly plucks a salmon or trout from a river. When bubble-net feeding Humpback Whales make sand lances boil to the ocean’s surface, other fish-eating specialists defer to Bald Eagles.
They seize ducks in open water and swim to shore to eat. They can chase down rabbits, hares and slower moving mammals. They eagerly scavenge deer and elk carcasses, where ravens, magpies and jays defer to them. Immature birds snack with the crows and gulls at municipal landfills.
“The Bald Eagle has evolved life-history strategies that include great diet plasticity,” said a team of Mississippi and Michigan wildlife biologists in the journal Northeastern Naturalist. They released a radio-collared a White-tailed Deer fawn along a river in the Upper Peninsula of Michigan, and found the collar and pieces of the fawn the following day “void of flesh” in a Bald Eagle nest with two eaglets.
In non-breeding seasons, especially when salmon are plentiful, Bald Eagles sometimes congregate in the hundreds or more.
Bald Eagle Congregations
The largest groups are found along the southeast Alaska coastline and Amchitka Island, British Columbia and the Canadian coastline, Besnard and Nemeiben Lakes in Saskatchewan, Yellowstone and Glacier National Parks (U.S.), Placentia Bay in Newfoundland, and the Snake River in Wyoming.
In these group settings, Bald Eagles resort to thievery. Stealing food is a sport – whether from each other or from other birds or animals. Why bother hunting when others deliver food to the party?
Usually an aggressor eagle accompanied by a less assertive accomplice, chase a third eagle carrying a salmon or other fish. The leader maneuvers to within 1 meter (3 ft) of the gift-bearing eagle, which soon drops its prey and escapes. The antagonist recovers the prize while the understudy takes mental notes.
Bald Eagles gain full adult plumage in their fifth year.
Wildside Nature Tours is leading a photography workshop adventure cruise in the summer to the panhandle of southeast Alaska to photograph Bald Eagles and many other birds, bears and feeding Humpback Whales. Participants can kayak, hike, fish and use Zodiacs to find wildlife and scenery to enjoy and photograph.
Bald Eagles perch on sea ice to wait for fish to surface. (Kevin Loughlin, Wildside Nature Tours)
Follow @topbirdingtours
The post Bald Eagles ‘Diet Plasticity’ Creates Varied Photo Opportunities appeared first on Top Birding Tours.