Carrion crow/hooded crow

Description

Carrion crows achieve a body length of 45 to 47 cm and a wingspan of 93 to 104 cm when fully grown. Their elevated, slightly curved and robust beak, their short, close-fitting thigh feathers and voluminous body plumage give them a compact, stocky appearance. Their wings are relatively long and moderately digitted, and their tails are broad and slightly rounded. The wing tips extend just beyond the tip of the tail when appressed. 

 The species occurs in a completely black and a black and gray plumage morph. Mixed forms of different characteristics may also occur. The black morph (C. corone corone) is characterized in fresh plumage by a dull, metallic sheen that ranges between green and blue and is less pronounced than in rooks (C. frugilegus) or ravens (C. corax), for example. The bases of the breast and belly feathers are light gray. With increasing time, the plumage loses saturation and luster and turns slightly brownish, especially on the wing feathers. The black and gray morph, called the hooded crow, matches the carrion crow in colouration of the head, central breast, tail, and wings. The nape, back, and shoulder coverts, on the other hand, are ash-gray to white, as are the small uppertail coverts, lateral breast, belly, and lower tail coverts. The thighs of hooded crows are feathered black, but are often covered by a grayish veil. Birds from the Mediterranean region show distinct black feather shafts in the white plumage areas.

The legs and the beak are slate-coloured in both morphs, and the iris of adult birds is dark brown. Juvenile carrion crows are distinguished from adults by their less voluminous plumage and somewhat slimmer silhouette. In addition, the colours of the plumage are tinted brownish, and in young hooded crows the black breast patch is also less pronounced than in adults.

Open and semi-open landscapes characterize the preferred habitats of carrion crows. The birds depend on trees, tall shrubs, or comparable anthropogenic structures as roosting, nesting, and perching sites. Regionally, rock cliffs may also serve this function. For foraging, they use wide-open, short-grass areas that are easy to survey, so both elements must occur in some proximity to each other. In forested areas, the species is therefore restricted to riparian areas, bogs and clearings; the deforestation of large parts of Eurasia in the Holocene, on the other hand, opened up new habitats for it, such as arable and pasture land, villages and cities. The revegetation of large European cities through parks and avenues allowed it to enter their centers from the 19th century onward. However, modern urbanization was initially slow for the carrion crow in Europe. Only with increasing prosperity and widespread availability of human waste in the second half of the 20th century were they able to establish themselves in larger numbers in cities. In the meantime, they usually occur there in higher population densities than in rural areas because of better food availability and less pressure from hunting and predators. The carrion crow inhabits a variety of very different habitats, but is generally absent from dense forests and steep slopes. An important locational factor is territories of goshawks, where carrion crows usually cannot breed successfully. The species occurs from sea level up to about 750 m, in some high mountains such as the Alps it can also be found at altitudes above 1000 m, sometimes even up to 2000 m.

The text is a translation of an excerpt from Wikipedia (https://de.wikipedia.org/wiki/Aaskrähe). On wikipedia the text is available under a „Creative Commons Attribution/Share Alike“licence. Status: 17 December 2021