The Golden Eagle (Aquila chrysaetos) is one of the best known birds of prey in the world. It is about 90 cm in length, has a wingspan of 220 cm and a weight of 5 kilos. Like all eagles, it belongs to the family Accipitridae.
Once the Golden Eagle lived in all temperate Europe, North Asia, North America, North Africa and Japan. In most areas this bird now is a mountain-dweller, but in former centuries it was also distributed in the plains and the forests.
There was a great decline in Central Europe, where the Golden Eagle now is restricted to the Alps. In Britain, there are about 500 birds left in the Scottish highlands. In North America the situation is not as dramatic, but there has been a noticeable decline as well.
A pair of Golden Eagles build several eyries within their territory. They use them alternately for several years. The nest consists of heavy tree branches, upholstered with grass.
Old eyries may be 2 metres in diameter and 1 metre in height, as the eagles enlarge their nests every year. If the eyrie is situated on a tree it may happen that the supporting tree branches break because of the weight of the nest.
The female lays two eggs between January and May (depending on the area). After 45 days the youngs hatch. They are entirely white and are fed for fifty days , then they are able to make the first flight attempts and eat on their own. In most cases only the older young survives, while the younger one dies before leaving the eyrie.
The couple remains together for life. They often have a division of labour while hunting: one partner drives the prey to the lurking other one. The prey is marmots, hares and mice, sometimes birds, martens, foxes and young deer. Large mammals like chamois or adult deers can only be taken if they are wounded or sick.
There are five subspecies of Golden Eagle: