Aquila chrysaetos
A large dark-brown bird of prey with a golden nape. It nests on the cliffs of the subalpine zone and hunts over the alpine pastures, mostly marmots. A pair defends a territory of several dozen square kilometres. Nearly gone in the 20th century, it has won back its place in the Alps.
Above an alpine pasture, a large dark shape circles effortlessly, its wings slightly raised in a V. On the slope, not a single marmot shows itself any more. The golden eagle can be recognised from afar by this soaring flight, its head held well forward and its fairly long tail.
The adult is an almost uniform dark brown; only its nape shades into golden ochre. Its bill is massive. The female is larger than the male. According to the Swiss Ornithological Institute, the golden eagle measures 75 to 88 cm, with a wingspan of 190 to 225 cm and a weight of 2850 to 6700 g.
It is associated with the high mountains, but it also lives lower down, in semi-open, little-farmed landscapes. According to the Swiss Breeding Bird Atlas, it builds its eyrie on a cliff, rarely in a tree, usually at an altitude of 1100 to 2200 m. Each pair holds a vast territory, generally of 20 to 80 km². According to the Swiss National Park, it often keeps several eyries there and fiercely chases intruders away.
In summer it hunts mainly marmots, according to the National Park; in winter, carrion makes up a large part of its diet. The Ornithological Institute has also shown that it regularly devours the entrails that big-game hunters leave on the spot. Mating takes place in January; in April the female lays two eggs, incubated for 43 to 44 days. When two eaglets hatch, in May, the stronger often shoves the weaker from the nest. The young bird fledges after 74 to 80 days, around the end of July, and its parents go on feeding it until the following winter.
Persecuted, the golden eagle came close to extinction. Shooting outside the hunting season was banned in 1926, but full protection only came in 1953, the Ornithological Institute points out: by then only about fifty pairs remained. Today the bird occupies the whole of the Alps, with 400 to 420 pairs (2025), and is reconquering the Jura, where, in 2009, a pair nested in the Solothurn Jura, a first in nearly two centuries. The country is home to a quarter of the eagles of the Alpine arc; yet the Red List rates the species as near threatened. Where territories meet, neighbours fight and pairs raise few young: in the Engadine, each pair raises on average only 0.3 young a year. Added to this are disturbance near the eyries and lead, swallowed with the remains of shot game.
Sources: Swiss Ornithological Institute, species account, text of the Swiss Breeding Bird Atlas 2013–2016 and articles “Histoire de la protection des oiseaux : l’aigle royal” [A history of bird protection: the golden eagle] and “Aigles empoisonnés par le plomb des munitions” [Eagles poisoned by lead from ammunition]; Swiss National Park, golden eagle portrait.
