Golden eagle
Aquila chrysaetos
— Where the name comes from
The Latin aquila derives perhaps from aquilus, “dark, brown”: the dark bird. The specific name is pure Greek, chrysáetos, “golden eagle”, from the gilded nape feathers that catch fire against the light.
— Facts
- Group
- Birds · Aves
- Order
- Diurnal birds of prey
- Habitat
- Mountains, rock faces, high-altitude grassland
- Range
- The northern hemisphere; in Italy in the Alps and the Apennines
- Size
- 75–90 cm, 190–230 cm wingspan
- Diet
- Carnivore — marmots, hares, young ungulates
- Lifespan
- 20–30 years
— Characteristics
- 01
In a stoop it passes 240 km/h.
- 02
The pair is faithful and reuses the same eyrie for decades, adding to it every year.
- 03
Its retina has about five times our density of photoreceptors.
— What sets it apart
The eagle has two foveae in each eye: one forward, one to the side. The sideways one, the sharper of the two, looks out about 40° off the axis of the head. To use it in flight the eagle would have to turn its head, which would slow it down. The answer is to come down in a spiral: an eagle’s spiralling stoop is not a flourish, it is how it keeps the prey in the good fovea without losing speed.
