Eastern Imperial Eagle
Aquila heliaca
Accipitriforme Order – Accipitridae Family
BIOMETRICS:
Length: 72-83 cm
Wingspan: 180-215 cm
Weight: 2400-4500 g
LONGEVITY: Between 21 and 45 years (variable)
DESCRIPTION:
Eastern Imperial Eagle adult has very dark brown plumage, sometimes with rufous tinge on upper shoulders. Head and neck feathers are very pale and typically lanceolate-shaped.
Usually, they are yellowish to creamy-white, and may appear completely white, mainly in the oldest eagles. Forehead is dark brown, almost black sometimes.
The main facts of its plumage are the pure white patches of shoulders, of varied size, and probably closely related to the age of the raptor. The leading edge is white too.
Undertail feathers are greyish, often almost white or spotted brown, with broad black terminal band, and white-tipped rectrices. Rest of plumage is dark brown, almost blackish.
Eyes are brown. Bill, legs and talons are yellow.
The juvenile has pale rufous plumage, with whitish throat and rump. The tail may be reddish-brown or greyish, with ochraceous-yellow tip. This colour disappears with the first moult.
Eyes are dark brown. Bill, legs and talons are yellow.
They reach the complete adult plumage between 6 and 8 years of age. The plumage may be very variable in colour for eagles of the same age. There are frequent individual variations, according to the age and the moult, and not due to specific establishing.
Female lays 2-3 eggs, often in early March, at the latest in May. Eggs are whitish with brown markings, or speckled grey and purple.
Incubation starts with the second egg. The two first chicks hatch simultaneously, and the third about four days later.
Incubation lasts about 43 days, by both adults, but mainly by female which is fed by male.
Very often, the third chick dies, but it occurs sometimes that the three may survive.
Young are aggressive as soon as they hatch. Usually, the older harasses the other which dies under the pecks. Often, the third egg ends under the talons and dejections of the elders, when it does not fall from the nest!
When they are 15 days old, the first feathers start to grow, and they replace the white down about one month later. The young need 55 days for reaching complete plumage, and they fledge at 60 days of age. They remain in the surroundings of the nest for one month more.
Then, they return to the same tree and are accepted by the adults, even after being separated during several months.
The young of the year remain in the vicinity of the territory, whereas the others disperse and move rarely more than 100 km.
DIET:
Eastern Imperial Eagle hunts rabbits and hares, but also fairly large birds, snakes and lizards. It also consumes carrion and recently dead domestic animals. It also takes fishes and insects. Preys may weight from 500 to 2500 grams.
PROTECTION / THREATS / STATUS:
The species is Endangered. Shooting and its outbursts, poisoning, removing of eggs and chicks, nest destruction play an important role in declines.
Eastern Imperial Eagle is protected, but the law is ineffective against the problems related to the reproduction, and the fights between the chicks.
The great development of agriculture, changes in biotope and human activities pose a big problem to this fairly small population.
Contamination by chemical products and pesticides involves infertile eggs.
Hope for conservation of correct numbers of pairs is found in Spain where most of the nests are situated within large properties while owners are concerned by this problem, and do all necessary to protect nests and birds.
Fr : Aigle Impérial
All : Kaiseradler
Esp : Águila Imperial Oriental
Ital : Aquila imperiale
Nd : Keizerarend
Russe : Могильник
Sd : Kejsarörn
Photographers:
Aurélien Audevard
OUESSANT DIGISCOPING
Niraj V. Mistry
Photo Galleries
Text by Nicole Bouglouan
Sources :
HANDBOOK OF THE BIRDS OF THE WORLD Vol 2 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334156
GUIDE DES RAPACES DIURNES – Europe, Afrique du Nord et Moyen-Orient de Benny Génsbol – Delachaux et Niestlé – ISBN : 2603013270
BirdLife International (BirdLife International)
Animal Diversity Web (University of Michigan Museum of Zoology)
Eastern Imperial Eagle
Second year
VOICE:
Eastern Imperial Eagle is rather silent, except during the breeding season. During the nesting period, it is very noisy, uttering bark-like sounds “rao,rao,rao”. Other harsh and very short calls may be heard, only one “kaok” in flight, and rapid “kokokoko” or “gock-gock-gock”.
HABITAT:
Eastern Imperial Eagle is found in open woodlands with thick understory, mixed with open areas for hunting all kinds of preys.
This species lives in mountainous areas, but not very high. It needs tall trees for nesting, and open lands or hills for hunting.
RANGE:
Eastern Imperial Eagle is found from south-eastern Europe to Central Asia, and in Spain (Spanish Imperial Eagle – Aquila adalberti).
European populations’ winter in northern tropical Africa, but most of them are partially migratory. Central Asian populations are migratory and winter in northern India.
BEHAVIOUR:
When perched, the Eastern Imperial Eagle seems to be lazy or indolent. It spends most of the day perched, as asleep, on a branch in tree or on high pole.
Both mates often hunt together. To feed, it easily captures preys on the ground. It always hunts in open lands. It flies at medium height and when the prey is detected, it swoops down in oblique dive, sometimes restraining itself, and slowing down before to attack its victim.
But while pursuing a bird in flight, if this bird flies to the cover or into foliage, the eagle will not continue, as to avoid the thick vegetation and branches against its body and plumage. It hunts between 10 am and midday, and from 17 pm to dusk.
The territory is variable in surface, but sometimes, we can find several pairs nesting close to each other, according to the prey’s availability.
But usually, pairs are separated and isolated through large territory, including mountain slope, understory and open area.
FLIGHT:
The Eastern Imperial Eagle flies up with flat spread wings (not in large V), being at right angle to the body. When soaring, wings are held straight, and while flapping, they are slightly angled forwards.
Seen from below, wings are rectangular, not rounded, and the tail is fairly short, usually closed.
While flying or soaring, it seems to be heavier and slower than the Golden Eagle. But adults are very agile and able to rise to great heights.
Flight displays occur in pairs. Male and female rise together while calling, then they dive one towards the other, and the bird below turns and holds the talons to its mate. They rarely touch them, drawing circles and calling at unison, ending by landing on the ground or in tree.
REPRODUCTION:
The Eastern Imperial Eagle builds the nest on trees, often cork-oaks, fairly low. It is a huge structure seen from a distance if on isolated tree. The same nest may be used during several consecutive years. It is about 1, 50 metres of diameter and about 60 cm thickness for a new nest. After several years, the volume becomes more important and bulky.
It is made with sticks, and lined with dry grasses and small green branches. Nest materials are carried by both adults, but the female arranges the interior. To build a new nest takes long time, and to repair a nest, about 10 to 15 days are necessary.
