As is common with raptorial species, the oldest chick will usually attack and kill its younger siblings within the first few days. The female lays on average 2 eggs, a couple of days apart in early spring. The nest itself can be up to 2 m in length, and pairs will return to the same nest year after year, repairing and improving it over time. They tend to prefer to build nests on cliff faces, but will build tree nests in some locations. Golden eagles are monogamous, and generally pair for life. By being larger, the female is better able to defend the nest against predators. In addition, the female spends more time incubating the nest and rearing the young than the male (although he does play a part in both). Therefore, it is in the female’s interest to be larger than her mate, in order to defend herself. With his sharp talons and strong beak, he could harm the female. In the early stages of pair formation, the male will often display aggressive behaviour. Perhaps the most compelling (although by no means definitive) explanation is to be found in courtship and nesting behaviour. However, this doesn’t explain why it is the female that is larger. The smaller male hunts for smaller prey, while the larger female hunts for larger prey, thus diversifying the food sources. One suggestion is that the difference reduces the competition for food between the sexes. The reason for this difference hasn’t been conclusively determined. In fact, the larger and more ferocious the raptor, the more pronounced is this difference. However, in predatory birds the opposite is true. In most birds, as with mammals, the female tends to be smaller than the male. Female wingspan can be up to 10% longer than that of the males, and they can weigh 40% more than their male counterparts. The golden eagle is neither the largest nor the heaviest bird of prey, however it displays the largest degree of inverse sexual dimorphism (where the female is larger than the male) of any bird in the Alps. They tend to fly in a shallow dihedral shape, meaning that the wings are held at in a slight ‘V’, as seen head on. In flight, these birds can be distinguished by their long fan-shaped tail, and short head. Young birds tend to be darker, with white stripes on the tail and white patches on the wings, which it will generally not lose until the bird reaches maturity at 5-6 years of age. Distinctive golden-brown feathers on the back of the head and neck give the bird its name. The adult plumage is a dark brown colour, with grey patches on the wings and tail. They can reach over 6kg, and their life expectancy in the wild is up to 30 years. The golden eagle is a large bird of prey, with a wingspan measuring about 1.8m-2.3m. Today golden eagles can be found in a variety of habitats from arctic to desert, across Europe, North and South America, Asia and parts of Africa. It is currently the national symbol of several countries, and is worshipped by native American Indians. The Aquila was the symbol used by ancient Roman legions. In ancient Greece the golden eagle was Zeus’ messenger and animal companion. The golden eagle is arguably the most famous of all raptors, and has been revered throughout history.
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