Sea eagle (Haliaeetus): overview, appearance, behavior and conservation

The term "sea eagle" refers to the group of large raptors in the genus Haliaeetus, often called ernes or erns. These birds are true bird[s] of prey that are strongly associated with aquatic environments: coastlines, estuaries, rivers and large lakes. Although many sea eagles specialize on fish, they are opportunistic hunters and scavengers rather than strict piscivores.

Appearance and identification. Sea eagles are robust, heavy-bodied eagles with long, broad wings, powerful feet and large hooked beaks. Size and plumage vary by species and age: many juveniles show mottled or darker feathers that become more uniform as adults. Several species, such as the bald eagle, develop distinctive contrasting head or tail colors when mature.

Distribution and habitat. Members of Haliaeetus have a wide but patchy distribution across Eurasia, Africa, Australasia and North America. They favor open water or shoreline where fish and waterbirds concentrate, and commonly nest in tall trees, on cliffs or on sea stacks close to feeding areas.

Diet and behavior. Sea eagles commonly hunt by flying low over water and snatching fish with outstretched talons, but they also take seabirds, mammals and carrion. Many species practice kleptoparasitism, stealing food from other birds, and will scavenge along coasts and riverbanks. Their flight is powerful and steady, marked by slow wingbeats and long glides.

Reproduction and lifespan. Sea eagles typically form long-term monogamous pairs. Nests are large stick structures, reused and added to year after year, sometimes reaching great size. Clutches are usually small (one to three eggs) and both parents contribute extended care; several species are long-lived in the wild when undisturbed.