The white-tailed sea eagle, one of the largest sea eagles, is widely spread across temperate regions of Eurasia. This powerful bird, belonging to the Accipitridae family, shares its group with other daytime raptors, including hawks, kites, and harriers.
Quick Facts
- Scientific Name: Haliaeetus albicilla
- Weight: 4.02 – 5.11 kg
- Length: 66 – 94 cm
- Wingspan: 1.78 – 2.45 meters
- Average Lifespan: 12 years
- Diet: Fish, birds, mammals, and more
Classification and Identification
As part of the eagle family, Accipitridae, these eagles are known for their hooked beaks, muscular legs, and sharp talons. Their remarkable vision allows them to spot prey from afar.
White-tailed sea eagles are the fourth largest birds of prey worldwide, boasting a wingspan of up to 2.45 meters. True to their name, adults have white tails and pale heads, while juveniles are more brown-toned and take eight years to develop adult plumage.
Sexual Dimorphism
Female white-tailed sea eagles are generally up to 15% larger and can weigh 25% more than males. This size difference likely serves to protect females from males during courtship, which can sometimes be aggressive.
Range and Habitat
These eagles are found throughout northern and central Europe, from Russia to Scandinavia. While central European populations tend to stay in place, northern ones are migratory, often wintering in southern Europe.
Preferring coastal and freshwater habitats, they can be found from lowlands to high elevations of up to 2,300 meters. They nest in areas with cliffs, forests, or wooded areas near food sources.
Diet and Hunting Techniques
White-tailed sea eagles primarily feed on fish and birds, often swooping from perches or diving shallowly to snatch prey from the water. When hunting fish like pike, they prefer smaller catches but have been known to “swim” larger fish to shore if they can’t lift them.
They target a variety of birds, most often mallards, especially those that are injured, in molting, or in dense vegetation.
In Norway, common eiders make up nearly 19% of their diet, with eagles exploiting eiders’ habit of diving rather than flying to escape. Some eider populations have even adjusted their routines to avoid eagle predation.
Mating and Nesting
White-tailed sea eagles form strong bonds with one mate at a time, with courtship peaking in spring and involving intricate “sky-dancing” displays. Nests, often large and built in high trees or on cliffs, can be used for many years, with location largely determined by nearby food availability. Each pair lays two to three eggs, with incubation primarily done by the female.
Chicks, covered in grey down at birth, take their first flights around 70 days and become proficient by 90 days. These young eagles mature at five to six years, often gathering with other juveniles in communal roosts, which are believed to help with future pair bonding.
Conservation History
Historically, white-tailed sea eagles faced heavy persecution across Western Europe, particularly as perceived threats to livestock, leading to their near extinction in many regions by the 20th century. The widespread use of DDT in the 1950s severely impacted their population by causing eggshell thinning, which led to high egg mortality.
Conservation Efforts and Reintroduction
Efforts to restore white-tailed sea eagle populations began in Sweden with uncontaminated feeding programs, which boosted breeding success. These eagles are now protected in much of their range, with Norway alone home to over 3,600 pairs—more than half of Europe’s population.
In the British Isles, reintroduction programs have reestablished breeding pairs, with over 130 pairs now residing in Scotland. Recently, a reintroduction program was launched on the Isle of Wight in England, where young birds from Scotland are being introduced over five years.
This program aims to bring the white-tailed sea eagle back to England’s skies, and early results look promising for this majestic species.
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