黄嘴山鸦种

亚种

普通黄嘴山鸦 Pyrrhocorax graculus digitatus：分布于西亚、中亚、南亚以及中国大陆的内蒙古、新疆、青海、甘肃、四川、西藏西藏等地。该物种的模式产地在叙利亚、黎巴嫩。

文化

音乐家奥立佛·梅湘创作的钢琴独奏曲集《鸟类图志》中的第1曲黄嘴山鸦以为题。

The Alpine chough (; chuf) or yellow-billed chough (Pyrrhocorax graculus) is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its two subspecies breed in high mountains from Spain eastwards through southern Europe and North Africa to Central Asia and Nepal, and it may nest at a higher altitude than any other bird. Its eggs have adaptations to the thin atmosphere that improve oxygen take-up and reduce water loss.

This bird has glossy black plumage, a yellow beak, red legs, and distinctive calls. It has a buoyant acrobatic flight with widely spread flight feathers. The Alpine chough pairs for life and displays fidelity to its breeding site, which is usually a cave or crevice in a cliff face. It builds a lined stick nest and lays three to five brown-blotched whitish eggs. It feeds, usually in flocks, on short grazed grassland, taking mainly invertebrate prey in summer and fruit in winter; it will readily approach tourist sites to find supplementary food.

Although it is subject to predation and parasitism, and changes in agricultural practices have caused local population declines, this widespread and abundant species is not threatened globally. Climate change may present a long-term threat, by shifting the necessary Alpine habitat to higher altitudes.

Taxonomy

The Alpine chough was first described as Corvus graculus by Linnaeus in the Systema Naturae in 1766. It was moved to its current genus, Pyrrhocorax, by English ornithologist Marmaduke Tunstall in his 1771 Ornithologia Britannica, along with the only other member of the genus, the red-billed chough, P. pyrrhocorax. The closest relatives of the choughs were formerly thought to be the typical crows, Corvus, and the jackdaws in the genus Coloeus, but DNA and cytochrome b analysis shows that the genus Pyrrhocorax, along with the ratchet-tailed treepie (genus Temnurus), diverged early from the rest of the Corvidae.

Description

The adult of the nominate subspecies of the Alpine chough has glossy black plumage, a short yellow bill, dark brown irises, and red legs. It is slightly smaller than the red-billed chough, at 37–39 centimetres (15–15 inches) length with a 12–14 cm (4.7–5.5 in) tail and a 75–85 cm (30–33 in) wingspan, but has a proportionally longer tail and shorter wings. It has a similar buoyant and easy flight. The sexes are identical in appearance, although the male averages slightly larger than the female. The juvenile is duller than the adult, with a dull yellow bill and brownish legs.

Distribution and habitat

The Alpine chough breeds in mountains from Spain eastwards through southern Europe and the Alps across Central Asia and the Himalayas to western China. There are also populations in Morocco, Corsica and Crete. It is a non-migratory resident throughout its range, although Moroccan birds have established a small colony near Málaga in southern Spain, and wanderers have reached Czechoslovakia, Gibraltar, Hungary and Cyprus.

This is a high-altitude species normally breeding between 1,260–2,880 metres (4,130–9,450 ft) in Europe, 2,880–3,900 m (9,450–12,800 ft) in Morocco, and 3,500–5,000 m (11,500–16,400 ft) in the Himalayas.

Behaviour and ecology

Breeding

The Alpine chough is socially monogamous, showing high partner fidelity in summer and winter and from year to year. Nesting typically starts in early May, and is non-colonial, although in suitable habitat several pairs may nest in close proximity. The bulky nests are composed of roots, sticks and plant stems lined with grass, fine twiglets or hair, and may be constructed on ledges, in a cave or similar fissure in a cliff face, or in an abandoned building.

Status

The Alpine chough has an extensive though sometimes fragmented range, estimated at 1–10 million square kilometres (0.4–3.8 million sq mi), and a large population, including an estimated 260,000 to 620,000 individuals in Europe. The Corsican population has been estimated to comprise about 2,500 birds. Over its range as a whole, the species is not believed to approach the thresholds for the global population decline criteria of the IUCN Red List (i.e., declining more than 30% in ten years or three generations), and is therefore evaluated as Least Concern.