The White-tailed Eagle (Haliaeetus albicilla), sometimes referred to as the Sea Eagle, is a large bird of prey found across temperate Eurasia. It is a member of the Accipitridae family, which includes other diurnal raptors such as hawks, kites, and harriers. This species is one of up to eleven members in the genus Haliaeetus, commonly known as sea eagles. It is also known by various names such as the ern, erne, gray sea eagle, and Eurasian sea eagle.
Adult White-tailed Eagles are distinguished by their greyish mid-brown plumage, paler head, neck, and upper breast, and a characteristic white tail. The bare parts of the body, including the bill, cere, feet, and eyes, are yellow. Juveniles are much darker brown with uneven white mottling, particularly on the underside and under-wing. The species exhibits sexual dimorphism, with females being larger than males.
White-tailed Eagles typically inhabit areas near large bodies of open water, including coastal saltwater regions and inland freshwater lakes, wetlands, bogs, and rivers. They require old-growth trees or ample sea cliffs for nesting.
The White-tailed Eagle's breeding range extends from Greenland and Iceland across Europe to as far east as Hokkaido, Japan. They are often scarce and spottily distributed as a nesting species, mainly due to human activities.
White-tailed Eagles are both powerful apex predators and opportunistic scavengers. They may migrate or disperse based on seasonal changes, with juveniles being more migratory than adults. The species is territorial, with pairs frequently engaging in aerial displays during the breeding season.
The White-tailed Eagle is vocal during the breeding season, with calls varying between males and females. Calls include a series of "gri-gri-gri" or "krick-krick-krick" for males and a deeper "gra-gra-gra-gra" or "krau-krau-krau-krau" for females.
White-tailed Eagles form lifelong pairs and breed in large nests constructed of sticks and branches. They typically lay two eggs, which are incubated primarily by the female. The species reaches sexual maturity at 5-6 years of age.
The White-tailed Eagle may be confused with the Bald Eagle and Steller's Sea Eagle, but differences in plumage and size are usually apparent. The species may also be mistaken for the Griffon Vulture at a distance due to vaguely similar coloring.
The diet of the White-tailed Eagle is varied and includes fish, birds, and mammals. They are known to hunt by forcing diving birds to repeatedly submerge until exhausted and can also scavenge carrion.
The White-tailed Eagle was once considered endangered or extinct in several countries but has recovered well in some populations due to governmental protections, conservation efforts, and reintroduction programs. The species is currently classified as Least Concern by the IUCN.