Sea eagles are magnificent birds of prey known for their impressive size and powerful hunting abilities. These raptors are deeply connected to aquatic environments, often seen soaring over coastlines, lakes, and rivers. They occupy a position at the top of the food chain. With their keen eyesight and formidable talons, sea eagles are skilled hunters, primarily preying on fish and other aquatic animals.
Physical Traits and Classification
Sea eagles are large birds, characterized by broad wingspans, powerful builds, and distinct plumage that often changes with age. Their size varies among species, with some, like the Steller’s Sea Eagle (Haliaeetus pelagicus), being among the heaviest eagles globally, weighing up to 9.5 kg (21 lb). The White-tailed Eagle (Haliaeetus albicilla) is Europe’s largest eagle, with a wingspan that can reach 2.5 meters (8.2 feet). These birds have large, hooked beaks and strong, unfeathered legs with sharp talons for grasping slippery prey.
Plumage coloration also varies, but many species exhibit a combination of dark brown or grey bodies with contrasting white on the head, tail, or underparts. For instance, adult White-tailed Eagles have a greyish-brown body with a distinctly paler head and a white, wedge-shaped tail. Juvenile sea eagles often display darker, more mottled brown plumage, gradually acquiring adult coloration over several years, sometimes taking up to five to eight years for full adult plumage to develop. The genus Haliaeetus includes eight species, such as the White-tailed Eagle, Steller’s Sea Eagle, and the well-known Bald Eagle (Haliaeetus leucocephalus) of North America.
Habitat and Hunting Behavior
Sea eagles are found across diverse aquatic environments globally, excluding South America and Antarctica. Their preferred habitats consistently involve large bodies of water, including coastlines, estuaries, large rivers, and lakes. For example, the White-tailed Eagle inhabits temperate regions with extensive lakes, coasts, or river valleys, often near undisturbed cliffs or large, mature trees for nesting. Steller’s Sea Eagles are endemic to coastal northeastern Asia, breeding along the Kamchatka Peninsula and the Sea of Okhotsk, and wintering in areas like Japan and Korea.
The primary diet of sea eagles consists mainly of fish. They are opportunistic hunters and also consume aquatic birds, small mammals, reptiles like turtles, crustaceans, and carrion. They often soar high above the water, using their exceptional eyesight to spot fish near the surface. Once prey is sighted, they swoop down, snatching fish from just below the water’s surface with their powerful talons. Sea eagles will also exploit commercial fisheries or readily available dead fish, especially salmon during spawning season, and are known to harass smaller birds to steal their catch.
Conservation Status
The conservation status of sea eagle populations varies among species. Factors such as habitat loss, pollution, and direct persecution have severely impacted their numbers. For example, the White-tailed Eagle was once extinct in Britain due to egg collecting, hunting, habitat destruction, and pesticide use. Similarly, the White-bellied Sea Eagle has experienced declines in parts of Southeast Asia and southeastern Australia, primarily due to human disturbance near nests and the removal of suitable nesting trees.
Despite these ongoing pressures, successful conservation efforts have led to recoveries in some regions. The White-tailed Eagle, for instance, has been successfully reintroduced to Scotland and England, with populations now estimated at 152 pairs in Scotland alone. Steller’s Sea Eagle is classified as “Vulnerable” by the International Union for Conservation of Nature (IUCN) due to habitat degradation, overfishing of prey, and lead poisoning, with its global population estimated to be around 3,500 to 4,500 mature individuals. Many sea eagle species are legally protected in their native countries, and key habitats are often established as nature reserves. The ban of harmful pesticides like DDT and PCBs has also been instrumental in the recovery of some populations.