[8] While found across a wide range, today breeding from as far west as Greenland and Iceland across to as far east as Hokkaido, Japan, they are often scarce and spottily distributed as a nesting species, mainly due to human activities.

These have included habitat alterations and destruction of wetlands, about a hundred years of systematic persecution by humans (from the early 1800s to around World War II) followed by inadvertent poisonings and epidemics of nesting failures due to various manmade chemical pesticides and organic compounds, which have threatened eagles since roughly the 1950s and continue to be a potential concern.

[12][13][14] White-tailed eagles usually live most of the year near large bodies of open water, including coastal saltwater areas and inland freshwater lakes, wetlands, bogs and rivers.

[6][24][25] Other groups, beyond milvine kites and Old World vulture, of modern accipitrids that are seemingly in some way related, albeit distantly, to the sea eagles include Accipiters, harriers, chanting-goshawks and buteonines.

Greenlandic white-tailed eagles (proposed as H. a. groenlandicus) form, on evolutionary time scales, a relatively recently founded population that has not yet accumulated many unique genetic characteristics and may not strictly fulfill the distinction of a subspecies.

As expected for many widely distributed animals of varied lineages, the white-tailed eagle conforms to Bergmann's rule in that more northerly birds tend to outsize those found relatively closer to the Equator.

[6] Juvenile and immature white-tailed eagles are a much darker brown than the adults and are more unevenly marked, with whitish feather edgings variably showing, mostly manifesting in some small areas of the underside and under-wing, with a narrow white axillary strip usually apparent.

[53] White-tailed eagles of all ages typically perch in quite upright positions on exposed branch, rock or other vantage point, but tend to sit more horizontally on the ground or other level surfaces.

[12][60] The cinereous vulture (Aegypius monachus) may too be considered superficially similar to the juvenile white-tailed eagle, but it is considerably larger and longer-winged and possesses a more uniform and darker hue with conspicuous paler legs and a relatively smaller head.

Their range extends to as far west as southern Greenland (prevented from breeding further north due to the short summers[63]), northern and western Iceland, and the reintroduced populations in some areas of England (re-established in 2019[64]), Ireland and Scotland, particularly conserved coastal spots.

They are said to be common around the White Sea, reportedly even the most abundant bird of prey locally and found both on coasts and inland lakes, although breeding rates are low due to the frigid weather.

[1][5] Intermittent forms of vagrancy and migration (most from eagles that breed in or disperse from Russia) are known to occur in several areas of Turkey, the Levant countries, Azerbaijan and Iran down to even the Persian Gulf, albeit seldom is the species to be found commonly or reliably anywhere in these regions.

[6][97] The species seldom migrates in the western part of its range, with eagles even breeding as far north as Greenland, Iceland and coastal Norway not moving at all for winter, but for some southward juvenile movements following dispersal.

[122] Since they do not have the waterproofing oils on the plumage of the more accomplished raptorial diver, the osprey (Pandion haliaetus), white-tailed eagles prefer not to get their feathers wet as it can take a long time for them to dry.

[111][115][109][152] In the United Kingdom, northern fulmar (Fulmarus glacialis) are noted as a common prey species and as such may contribute to locally high levels of DDT and PCB chemicals in nesting eagles.

[6][110][116][162][141] They are reported to have attacked and eaten the largest seabirds they encounter, such as great cormorants (Phalacrocorax carbo), and in some cases, such as in the Baltic Sea, have nearly destroyed whole colonies, from the eggs to the adults which average about 2.57 kg (5.7 lb).

In some of the coldest climes of Russia, such as in the Ural mountains or the Kola peninsula, white-tailed eagles have been recorded to live on surprisingly high numbers of small rodents, comprising 13.8% and more than 21% of all prey remains, respectively.

[130] In only the white-tailed eagles nesting in Hokkaido, they've been known to hunt large cephalopods such as robust clubhook squid (Onykia robusta) and giant Pacific octopus (Enteroctopus dofleini), though likely mainly younger specimens and those collected and perhaps injured by large-scale fishing operations.

White-tailed eagles frequently engage during early spring variously in soaring, sky-dancing and other aerial displays, all with much loud calling, often performed by pair members together, including spectacular mutual cartwheel downwards where talons touch or interlock.

[34] Fischer noted 8–9 pairs on the small Norwegian island of Nord-Fugløya due to its huge seabird colonies, with late summer numbers boosting to 75 eagles, all within an area of only 22 km2 (8.5 sq mi).

[35] After his final display, the female crouches low, almost flat, with her head and neck outstretched, wings half open, and tail held level with the rest of the body.

Avian predation, overall a seemingly rare occurrence, of white-tailed eagle eggs and nestlings have been reported as crows, common ravens, and western marsh harriers, which are likely to succeed in cases where nest attendance is low or if successful in driving away the parents via fierce mobbing.

[245][246] In eastern Germany, of 194 white-tailed eagles found dead between 1946 and 1972, of those where cause of death could be determined, 39% had been shot, accidents (especially powerlines) accounted for 6%, territorial disputes 7.5% and conservatively 13% were from poisoning.

[41] In Britain, the opinion towards white-tailed eagles became negative in sync with the creation of farmland and commercial fishing, as it was quickly perceived that they were competitors for resources and could deplete the livelihood of flocks for shepherds, which is largely untrue and game animals for gamekeepers.

[262] In order to offset the numerous chemical and metal based poisoning that humans were inadvertently exposing the species to, a widespread operation was undertaken to feed white-tailed eagles uncontaminated foods in Sweden.

Here, carcasses from slaughterhouses placed in areas free of human disturbance, usually fields, bogs, marshes or frozen lakes, from October to March (after these months, the eagles will ignore carrion in favour of capture of live prey).

[268] The residuals of mercury from various fungicides (now banned), air particles and pollution run-off water have caused huge concentrations in fish of many different areas, which continues to effect humans as well as entire ecosystems of wildlife.

[272] Reintroduction efforts succeeded in the Bohemia area of the Czech Republic as well, where the biologists similarly followed the guidelines of guarding of occupied eyries and provision of safe foods.

"[280] The first white-tailed eagle breeding pair since 1912 nested one hundred years later on Lough Derg (Loch Deirgeirt), marking a great success for the Irish reintroduction programme.

[292][293][294] In a recovering population in north-east Germany, a trade-off between the distance to neighbouring breeding pairs and to the nearest water body (the birds' favoured foraging habitat) was found.