White-tailed eagle

The white-tailed eagle (Haliaeetus albicilla), sometimes known as the "sea eagle", is a large bird of prey found across temperate Eurasia. It belongs to the family Accipitridae, which includes other birds like hawks, kites, and harriers. There are up to eleven species called sea eagles, and this one is also called the white-tailed sea-eagle, ern, erne, gray sea eagle, or Eurasian sea eagle.

These eagles live near large bodies of water such as coastal saltwater areas, freshwater lakes, wetlands, bogs, and rivers. They need tall, old trees or sea cliffs for nesting and eat mainly fish and water birds. They are strong hunters but also sometimes eat food left by other animals.

In the past, white-tailed eagles were harmed by human actions such as changing their habitats, destroying wetlands, and using harmful pesticides. Because of this, their numbers dropped in many places. However, thanks to protection efforts by governments, conservationists, and careful reintroductions, some populations have begun to grow again. These eagles are powerful predators and share a similar way of living with the bald eagle found in North America.

Taxonomy

The white-tailed eagle was first described by the Swedish naturalist Carl Linnaeus in 1758. Its scientific name Haliaeetus means "sea-eagle". This comes from old words for "sea" and "eagle". The species name albicilla refers to its white tail. This bird has many names in different languages, such as erne in Anglo-Saxon, which means "soarer".

Systematics

The white-tailed eagle belongs to the genus Haliaeetus, which includes 11 living species. It is closely related to the lesser and grey-headed fish eagle. These fish eagles mainly eat fish and live in wooded, mountainous areas. They look different from other sea eagles, being slimmer, longer-tailed, and more uniformly grey.

The white-tailed eagle is also related to the bald eagle. These two species likely separated from other sea eagles around the early Miocene period, about 10 million years ago. They probably started in the North Pacific and then spread westward into Eurasia and eastward into North America. Like another large northern species, Steller's sea eagle, adult white-tailed eagles have yellow feet, beaks, and eyes.

Description

The white-tailed eagle is one of the largest birds of prey. It is the largest eagle in Europe and one of the largest in the world. It is smaller than the Steller's sea eagle, harpy eagle, and Philippine eagle. This bird can be 66 to 94 cm long, with a wingspan from 1.78 to 2.45 meters. Males weigh between 3.1 to 5.4 kg, and females weigh from 4 to 6.9 kg.

White-tailed eagles look special. Adults are mainly greyish-brown with a pale head and neck, and they have a white tail. Their wings are very broad, and they are good at soaring. These eagles make calls, especially during the breeding season. Males and females have different calls and often use them together.

Distribution and habitat

White-tailed eagles live in many parts of northern Europe and Asia. They breed in places like Norway, Finland, Sweden, and Denmark, as well as many islands and coastal areas. They are also found in Russia, stretching all the way to the Bering Sea. Some live in Turkey, Iran, and parts of Central Asia.

These birds prefer areas near water, such as coasts, lakes, and rivers. They like to nest in tall trees or on cliffs and can be found in both remote forests and sometimes near human communities, especially if the area is protected.

Behaviour

White-tailed eagles often sit on trees or rocks for long periods. They fly high in the sky and also sit near water or wet areas, but they fly less than golden eagles. These eagles like to sleep near their nests, choosing spots like rocks, trees, or ledges.

Young white-tailed eagles may fly far from where they were born, especially in Europe, while adults usually stay close to their nests all year. In some places, these eagles travel far to spend the winter in warmer areas. During winter, they sometimes gather in groups, especially younger birds. These eagles protect their homes strongly, and males may fight if another eagle comes too close.

Dietary biology

The white-tailed eagle eats different foods depending on the season. They mainly eat fish and birds, but also eat mammals, especially when there is less fish in winter. These eagles are strong hunters and can catch large animals, but they often look for easier targets.

White-tailed eagles are good at fishing, especially in shallow water, and they also find dead fish and other animals to eat. They can eat a lot at once, sometimes as much as 10% of their body weight in one meal. Their diet includes many types of fish, such as pike and bream, and many kinds of birds, including ducks, geese, and even larger birds like swans and herons.

In some places, mammals like rabbits and hares are a big part of their diet, especially when other food is hard to find. They can also eat small rodents, sometimes even tiny ones like shrews. Occasionally, they might eat other animals like reptiles or amphibians, but this is less common.

Overall, white-tailed eagles are flexible hunters, able to find food in many different ways, which helps them live in various habitats.

Breeding

White-tailed eagles breed between January and July in the south and from April to September in the north. These birds mate for life. They often show off in the sky and call to each other.

They build big nests in tall trees or on cliffs. These spots give them good access to food and safety.

Eggs are laid between January and May, depending on where they live. Most nests have two eggs. The female sits on the eggs for about six weeks. The chicks hatch, and both parents take care of them. The male often brings food. The young birds stay with their parents for several months after they can fly, learning to hunt and survive on their own.

Relationship with humans

The white-tailed eagle once lived across much of Europe and parts of Africa but their numbers dropped a lot from the 19th century onward. By the early 1900s, they were almost gone from Europe except in places like Fennoscandia, mainly Norway, and some spots in eastern Europe. They disappeared completely from the British Isles.

People sometimes didn’t like white-tailed eagles because they thought the birds would harm livestock or compete with fishermen. This led to rules that allowed people to kill the eagles. Many eagles were killed using traps and guns. Also, chemicals used in farming made it hard for the eagles to have healthy chicks. Pollution also caused problems.

Conservation work has helped the white-tailed eagle recover in many places. Protecting their nests, giving them clean food, and making laws against harming them have been important. In some areas, like Scotland and Ireland, people have been releasing young eagles to help the population grow. These efforts have worked well, and eagles are now breeding in places where they hadn’t for many years.

Some threats still exist today. In places like Scotland, some people still illegally kill eagles, and wind turbines can sometimes harm eagles. But overall, conservation work has been helping, and white-tailed eagle numbers are rising in many places.

Heraldry

The white-tailed eagle has been in stories and art for a very long time, especially in old Saxon culture. Many places are named after this big bird. It might be the white eagle in the Polish coat of arms. In pictures, the sea eagle often holds a fish, usually a pike, to show it is different from other eagles.

The white-tailed eagle is also in the coat of arms of Kumlinge and Åland.

Prehistory

On Orkney, Scotland, scientists found bones of sea eagles in old burial mounds. These mounds are about 6,000 years old. One of these places is called the Tomb of the Eagles. This shows that ancient people respected these birds. There are also old carvings made by the Picts that show sea eagles. In Krapina, scientists found marks on the talons of white-tailed eagles. These marks show that Neanderthals may have used the eagles as jewellery.

Folklore

In the Shetland Isles, Scotland, some fishermen believed that when a white-tailed eagle appeared, fish would come to the surface. Because of this belief, some fishermen would use eagle fat on their bait, hoping it would help them catch more fish.