[order] Falconiformes | [family] Accipitridae | [latin] Hieraaetus pennatus | [UK] Booted Eagle | [FR] Aigle botté | [DE] Zwergadler | [ES] Aguililla Calzada | [IT] Aquila minore eurasiatica | [NL] Dwergarend

Dwergarend determination

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A small eagle, about the size of the Common Buzzard. In its pale phase the adults have blackish flight feathers contrasting with white under side, vaguely resembling the Egyptian Vulture. Dark phase birds are easy to confuse with Wahlberg's Eagle in Africa and melanistic Changeable Hawk-eagle in the East, but are smaller than either, a more variegated brown and more stockily built. Immatures are paler rufous below than those of Ayre's Hawk-eagle or Bonelli's Eagle.
It is a very dashing and attractive little eagle, with very swift flight, often diving into and weaving in and out among tree tops.

The Booted Eagle is a woodland bird, inhabiting both deciduous and coniferous timber, generally in mountainous country up to 10,000 feet, but sometimes also on plains at sea level. it prefers forest patches with clearings or open regions with isolated trees from south-western Europe and northern Africa to central Asia

Hieraaetus pennatus is a widespread summer visitor to much of south-west and eastern Europe, which accounts for less than half of its global breeding range. Its European breeding population is small (as few as 4,400 pairs), but was stable between 1970-1990. Trend data were not available for the key Spanish population during 1990-2000, but despite declines in much of south-east Europe, the species probably remained stable overall. Nevertheless, its population size still renders it susceptible to the risks affecting small populations.
It is wintering in sub-Saharan Africa. The population of the European Union is estimated at 2450-4950 breeding pairs. In France and the Iberian Peninsula it seems fairly stable, but everywhere else it is declining following degradation and loss of habitat.

Feeds on small to medium-sized birds, lizards (particularly in Spain), and small mammals; occasionally insects. Captures prey by swift dive into foliage followed by agile pursuit through branches. Also soars over open countryside, swooping at prey on ground, often with great force. Birds range in size from warblers to domestic hen.

This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population estimated to be 10,000-100,000 individuals (Ferguson-Lees et al. 2001). Global population trends have not been quantified; there is evidence of a population decline (Ferguson-Lees et al. 2001), but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]

From the beginning of the breeding season, and during and after it, the birds perform very spectacular nuptial displays. The main feature is a series of dives followed by upward swoops, performed at great speed and accompanied by much calling. The male may dive at the female repeatedly, and she may turn on her back and present her claws upwards to his. A variant of display may be a long swift glide, with the feet sometimes hanging limp, ending in a tree or in a sudden swoop up into the air again. Looping has been recorded in display.
The nest is usually built in trees, 20-50 feet up, and is a solid structure of sticks about three to four feet across and two feet deep, lined with sprigs of pine or green leaves. Where trees are scarce, crags may be used. It is used year after year, and a pair may have more than one nest. Two eggs are normally laid, sometimes one, at intervals of several days.
Incubation begins with the first egg - the female only sitting. There is considerable difference in size in the young, and only one usually survives. The male brings food to the nest site during both the incubation period and the fledging period. The young are out of the nest by early August, indicating a total breeding time from eggs to fledging of about three months. The young accompany their parents in the territory for some time after making their first flight.

Migratory. Exceptionally winters in southern Spain, France, Greece, Crete, and Israel, also occasionally in north-west Africa and Egypt. The great majority of west Palearctic breeders are trans-Saharan migrants. African winter quarters extend from forested savannas of Ethiopia and central Sudan southwards to South Africa, and westwards through Chad and Nigeria to Burkina Faso (Upper Volta), Mali, Senegal, and Ivory Coast. The total winter range is large, but thinly distributed almost everywhere else.
The southward departures start late August, and European breeding grounds are deserted by mid-October, although some birds persist in Turkey, northern Iran, southern France, and north-west Africa into November. First birds return to breeding grounds in north-west Africa in February (most in March), in France in late March, in Turkey and Iran in early April, and Hungary in mid-April. European breeding populations enter and leave continent mainly via short sea-crossings of Bosporus and Straits of Gibraltar, and around eastern end of Black Sea, though also regular passage across Sicilian Channel between Italy and Tunisia. Small numbers may also cross Mediterranean at wider points as shown by occurrences on Balearic Islands, Malta, and Crete. Straits of Gibraltar passage is the largest, involving population of Iberia and France, main autumn passage there mid-September to early October. Return movement protracted, probably due to immature birds; from mid-March to end of May.