Although a Bald Eagle is massive, has excellent eye sight, powerful leg muscles and strong talons to grip prey with, their predilection for foraging for live prey (mostly fish but also mammals, birds and reptiles) isn’t as great as one might imagine. Often they (particularly immature eagles who lack experience foraging) resort to scavenging dead animals or stealing prey from other birds rather than capturing live prey. Marauded birds include ospreys and herons which are better at capturing live fish and aren’t particularly good at defending themselves.
What seems fitting given that eagles secure much of their food from other birds is that they in turn provide many birds and predators with a meal . Crows, ravens, coyotes, bobcats, and foxes all are known to move in when they become aware of an easy dinner. Eagles are said to be easily displaced by these species at scavenging sites. The pictured American Crows, however, are patiently waiting their turn. (Photo: American Crows waiting for 2nd year Bald Eagle to finish feeding on a fish; inset – Bald Eagle’s 5″-long tracks)
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How do herons, egrets, bitterns, kingfishers, loons and other fish-eating birds with spear-shaped bills capture their prey? Do they use their bill as a spear and pierce through a fish, or do they grab the fish between their mandibles? You often read about one of these birds “spearing” a fish. However, a majority of these birds, most of the time, do not spear fish, but open and shut their bills fast enough to capture a fish in them — the spear shape of their bill lends itself to the tong-like action it performs. In addition, its shape enhances the movement of the bill through the water as the bird dives (its head or body) into the water to grasp the fish between its upper and lower mandibles.
One exception to this rule is the Anhinga, which does run its bill (which is equipped with backward grooves to prevent slippage) through fish in order to capture them. After spearing a fish, an Anhinga then shakes it vigorously off its bill, tosses it in the air, and catches and swallows it headfirst. (Photo: Great Blue Heron)