Alpine chough
Alpine chough | |
---|---|
Adult of nominate subspecies in Switzerland | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Corvidae |
Genus: | Pyrrhocorax |
Species: | P. graculus
|
Binomial name | |
Pyrrhocorax graculus (Linnaeus, 1766)
| |
Approximate distribution shown in green | |
Synonyms | |
Corvus graculus Linnaeus, 1766 |
The Alpine chough (
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
The genus name is derived from Greek πύρρος (purrhos), "flame-coloured", and κόραξ (korax), "raven".[7] The species epithet graculus is Latin for a jackdaw.[8] The current binomial name of the Alpine chough was formerly sometimes applied to the red-billed chough.[9][10] The English word "chough" was originally an alternative onomatopoeic name for the jackdaw, Corvus monedula, based on its call. The red-billed chough, formerly particularly common in Cornwall and known initially as the "Cornish chough", eventually became just "chough", the name transferring from one genus to another.[11]
The Alpine chough has two extant subspecies.
- P. g. graculus, the nominate subspecies in Europe, north Africa, Turkey, the Caucasus and northern Iran.[4]
- P. g. digitatus, described by the German naturalists Wilhelm Hemprich and Christian Gottfried Ehrenberg as P. alpinus var. digitatus in 1833,[12] is larger and has stronger feet than the nominate race.[4] It breeds in the rest of the depicted Asian range, mainly in the Himalayas.[13]
Moravian palaeontologist Ferdinand Stoliczka separated the Himalayan population as a third subspecies, P. g. forsythi,[14] but this has not been widely accepted and is usually treated as synonymous with digitatus.[15][16] A Pleistocene form from Europe was similar to the extant subspecies, and is sometimes categorised as P. g. vetus.[17][18][19]
The Australian white-winged chough, Corcorax melanorhamphos, despite its similar bill shape and black plumage, is only distantly related to the true choughs.[20]
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.[4] 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.[13] 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.[4] The Alpine chough is unlikely to be confused with any other species; although the jackdaw and red-billed chough share its range, the jackdaw is smaller and has unglossed grey plumage, and the red-billed chough has a long red bill.[13]
The subspecies P. g. digitatus averages slightly larger than the nominate form, weighing 191–244 g (6.7–8.6 oz) against 188–252 g (6.6–8.9 oz) for P. g. graculus, and it has stronger feet.[4][13] This is in accordance with Bergmann's rule, which predicts that the largest birds should be found higher elevations or in colder and more arid regions. The extremities of the body, the bill and tarsus, are longer in warmer areas, in line with Allen's rule. Temperature seems to be the most important cause of body variation in the Alpine chough.[21]
The flight of the Alpine chough is swift and acrobatic with loose, deep wing beats. Its high manoeuvrability is accomplished by fanning the tail, folding its wings, and soaring in the updraughts at cliff faces. Even in flight, it can be distinguished from the red-billed chough by its less rectangular wings, and longer, less square-ended tail.[13][22]
The
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.[4]
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
In the western Italian Alps, the Alpine chough nests in a greater variety of sites than red-billed chough, using natural cliffs, pot-holes and abandoned buildings, whereas the red-billed uses only natural cliffs (although it nests in old buildings elsewhere).[4][25][33] The Alpine chough lays its eggs about one month later than its relative, although breeding success and reproductive behaviour are similar. The similarities between the two species presumably arose because of the same strong environmental constraints on breeding behaviour.[25]
A study of three different European populations showed a mean clutch size of 3.6 eggs, producing 2.6 chicks, of which 1.9 fledged. Adult survival rate varied from 83 to 92%, with no significant difference detected between males and females. Survival of first-year birds was, at 77%, lower than that of adults. The availability or otherwise of human food supplied from tourist activities did not affect breeding success.[28]
Feeding
In the summer, the Alpine chough feeds mainly on
This bird always forages in groups, which are larger in winter than summer, and have constant composition in each season. Where food resources are restricted, adults dominate young birds, and males outrank females.[28] Foraging areas change altitudinally through the year, depending on climatic factors, food availability and food quality. During the breeding season, birds remain above the tree line, although they may use food provided by tourists at refuges and picnic areas.[34]
Movement to lower levels begins after the first snowfalls, and feeding by day is mainly in or near valley bottoms when the snow cover deepens, although the birds return to the mountains to roost. In March and April the choughs frequent villages at valley tops or forage in snow-free patches prior to their return to the high meadows.[34] Feeding trips may cover 20 km (12 mi) distance and 1,600 m (5,200 ft) in altitude. In the Alps, the development of skiing above 3,000 m (9,800 ft) has enabled more birds to remain at high levels in winter.[13]
Where their ranges overlap, the two chough species may feed together in the summer, although there is only limited competition for food. An Italian study showed that the vegetable part of the winter diet for the red-billed chough was almost exclusively
Natural threats
Predators of the choughs include the peregrine falcon, golden eagle and Eurasian eagle-owl, while the common raven will take nestlings.[39][40][41][42] Alpine choughs have been observed diving at a Tibetan red fox. It seems likely that this "mobbing" behaviour may be play activity to give practice for when genuine defensive measures may be needed to protect eggs or young.[43]
The Alpine chough is a host of the widespread bird
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.
At the greatest extent of the
Choughs can be locally threatened by the accumulation of
References
- ^ . Retrieved 19 November 2021.
- ^ Linnaeus, C. (1766). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima (in Latin). Holmiae. (Laurentii Salvii). p. 158.
- ^ Tunstall, M. (1771). Ornithologia Britannica: seu Avium omnium Britannicarum tam terrestrium, quam aquaticarum catalogus, sermone Latino, Anglico et Gallico redditus (in Latin). London, J. Dixwell. p. 2.
- ^ ISBN 978-0-7136-3999-5.
- ^ ISBN 978-0-565-00771-3.
- .
- ^ "Chough Pyrrhocorax pyrrhocorax [Linnaeus, 1758]". BTOWeb BirdFacts. British Trust for Ornithology. Archived from the original on 11 April 2016. Retrieved 6 February 2008.
- ISBN 978-0-7100-9267-0.
- ^ Lilford, Thomas Littleton Powys; Salvin, Osbert; Newton, Alfred; Thorburn, Archibald; Keulemans, Gerrard John (1897). Coloured figures of the birds of the British islands. Vol. 2. R. H. Porter. p. 56.
- ^ Temminck, Coenraad Jacob (1815–40). Manuel d'ornithologie; Tableau systématique des oiseaux qui se trouvent en Europe. Paris: Sepps & Dufour. p. 122.
- ISBN 978-0-7011-6907-7.
- ^ Dickinson, E C; Dekker, R. W. R. J.; Eck, S.; Somadikarta S. (2004). </a> "Systematic notes on Asian birds. 45. Types of the Corvidae". Leiden Zoologische Verhandelingen. 350: 121.
- ^ ISBN 978-0-19-854099-1.
- ^ Stoliczka, Ferdinand (1874). "Letter to the Editor, 10 September 1873, Camp Leh". Stray Feathers: A Journal of Ornithology for India and Its Dependencies. 2 (4): 461–463.
- hdl:2246/3595.
- ISBN 978-84-87334-67-2.
- ^ (Hungarian with English abstract) Válóczi, Tibor (1999) "Vaskapu-barlang (Bükk-hegység) felső pleisztocén faunájának vizsgálata (Investigation of the Upper-Pleistocene fauna of Vaskapu-Cave (Bükk-mountain)). Folia historico naturalia musei Matraensis 23: 79–96
- ISBN 80-901105-3-8p. 238
- .
- ^ "ITIS Standard Report Page: Corcorax". Integrated Taxonomic Information System. Retrieved 5 February 2008.
- .
- ISBN 978-0-246-12440-1.
- S2CID 85866352.
- JSTOR 1366724.
- ^ .
- ISBN 978-0-486-42888-8.
- S2CID 41532963.
- ^ .
- ISBN 978-0-00-219249-1.
- ISBN 978-0-19-510608-4. Archived from the original(PDF) on 16 December 2008.
- S2CID 27372255.
- .
- hdl:10261/58104.
- ^ a b c Laiolo, Paola; Rolando, Antonio; Carisio, Lorendana (2001). "Winter movements of the Alpine Chough: implications for management in the Alps" (PDF). Journal of Mountain Ecology. 6: 21–30. Archived from the original (PDF) on 5 July 2007.
- ^ McKibbin, René; Bishop, Christine A. (2008). "Feeding observations of the western Yellow-breasted Chat in the south Okanagan valley British Columbia, Canada during a seven-year study period" (PDF). British Columbia Birds. 18: 24–25.
- .
- ISBN 978-0-226-84735-1.
- ^ Laiolo, Paola (2003). "Ecological and behavioural divergence by foraging Red-billed Pyrrhocorax pyrrhocorax and Alpine Choughs P. graculus in the Himalayas". Ardea. 91 (2): 273–277. Archived from the original on 12 June 2012. Retrieved 2 June 2009. (abstract)
- ^ "A year in the life of Choughs". Birdwatch Ireland. Archived from the original on 11 April 2016. Retrieved 6 February 2008.
- ^ "Know Your Crows". Operation Chough. Archived from the original on 14 July 2014. Retrieved 5 July 2014.
- .
- S2CID 38852266.
- ^ Blumstein, Daniel T.; Foggin, J. Marc (March 1993). "Playing with fire? alpine choughs play with a Tibetan red fox". Journal of the Bombay Natural History Society. 90: 513–515.
- ^ Rothschild, Miriam; Clay, Theresa (1953). Fleas, flukes and cuckoos. A study of bird parasites. London: Collins. pp. 89, 95.
- ^ (Russian) Georgiev B. B.; Kornyushin, VV.; Genov, T. (1987). "Choanotaenia pirinica sp. n. (Cestoda, Dilepididae), a parasite of Pyrrhocorax graculus in Bulgaria". Vestnik Zoologii. 3: 3–7.
- S2CID 81701158. Archived from the originalon 27 January 2021. Retrieved 22 February 2013.
- ISSN 0002-4619.
- ISBN 978-0-19-921751-9.
- .
- ^ a b Stoyanov, Georgi P.; Ivanova, Teodora; Petrov, Boyan P.; Gueorguieva, Antoaneta (2008). "Past and present breeding distribution of the alpine chough (Pyrrhocorax graculus) in western Stara Planina and western Predbalkan Mts. (Bulgaria)" (PDF). Acta Zoologica Bulgarica. Suppl. 2: 119–132.
- S2CID 21498755.
- ^ Pain, Debbie; Dunn, Euan (1996). "The effects of agricultural intensification upon pastoral birds: lowland wet grasslands (The Netherlands) and transhumance (Spain)". Wader Study Group Bulletin. 81: 59–65.
- S2CID 36864195. Archived from the original(PDF) on 19 July 2015. Retrieved 24 May 2009.
- ^ Reyes, Juan Carlos Rando (2007). "New fossil records of choughs genus Pyrrhocorax in the Canary Islands: hypotheses to explain its extinction and current narrow distribution" (PDF). Ardeola. 54 (2): 185–195.
External links
(Alpine chough).
- Ageing and sexing (PDF; 0.86 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze
- Alpine chough videos, photos & sounds on the Internet Bird Collection
- [1]