Big-billed crow

Big-billed crow
Big-billed crow ( Corvus macrorhynchos )
Systematics
Order : Passerines (Passeriformes) Subordination : Songbirds (passeri) Superfamily : Corvoidea Family : Corvids (Corvidae) Genre : Ravens and Crows ( Corvus ) Type : Big-billed crow
Scientific name
Corvus macrorhynchos
Wagler , 1827

The big-billed crow ( Corvus macrorhynchos ) is a species, possibly also a group of closely related species, from the genus of ravens and crows ( Corvus ), which is common in large parts of eastern Asia.

features

Appearance and build

The body length is between 45 and 59 cm, with males a little larger than females and animals spread in the north and at higher altitudes larger than animals in the south and in the lowlands. They can weigh between 450 and 1000 grams. The plumage appears monochrome, glossy black, depending on the region, with a purple, blue or green shimmer that is due to structural colors. This coloring is absent in young animals. On closer inspection, not visible in the terrain, the base of the neck feathers is white or gray.

Big-billed crow ( C. c. Intermedius ) in Himachal Pradesh , India.

The black beak is long, the upper beak noticeably arched in front, especially in the male. In the contour it connects to the face with a noticeable step. The iris is dark brown, the legs black. The wings are relatively wide, shorter and wider than the real ravens, which are common sympatric . The tail mostly rectangular, somewhat wedge-shaped in animals from the Himalayas; this can only be seen in flight when the tail feathers are spread.

Vocalizations

The sounds of the thick-billed crow are similar to those of the great- billed crow . But they are generally deeper and more sonorous than those of their relatives. Usually she utters a loud "kaaa-kaaa-kaaa". But the crow utters many other calls, e.g. B. those that are described as "kau kau" and those that can be confused with the drumming of woodpeckers .

distribution

The distribution area extends in the north to the Kuriles , the island of Sakhalin and the adjacent eastern Siberia via eastern China, Japan, the Himalayas (Afghanistan and northern Pakistan), over almost all of Southeast Asia to Java, Sumatra and Timor in the south. Also, Sri Lanka and the Andaman Islands are inhabited. In the west the distribution area stretches narrowly along the coast to Pakistan, in former times occasionally to the Iranian Gulf coast. The species reaches more than 5,000 meters above sea level in the Himalayas.

habitat

It lives in forests, parks, gardens and urban regions with trees.

behavior

nutrition

The birds are extremely variable in the way they eat. Animal and vegetable foods that you can find on the ground or on trees come into question.

In urban areas of Japan they are perceived as a nuisance because they tear open rubbish bags and look for food in them. They are more specialized in cities and settlements than carrion crows. In India they are less common in settlements than the similar golden crow ( Corvus splendens ) and are more likely to be found in tree-lined rural regions or small villages.

Courtship, nest building and brood care

Big-billed crows form tight pairs and nest individually. To search for food, the animals often form small groups, in India also together with bright crows. Outside of the breeding season, the animals often form large flocks that rest together. In the breeding season, the pairs defend territories, not only against conspecifics, but also against other species of crow such as the carrion crow ( Corvus corone )

The nest is built on branches very high in a tree. Trees at the edge of the forest are preferred, but individual trees are also accepted, including those in settlements. Grass, wool, scraps of clothing, vegetable fibers and similar materials are also used as material for building nests. The nest is made in a fork of the tree and has the shape of a flat cup. Both sexes participate in the nest construction.

The clutch contains four to five, rarely up to seven eggs. The eggs are round to slightly oval. The base color is a pale blue-green and the eggs are reddish brown, pale sepia and gray speckled, speckled and streaked. They have a size of 2.7 cm to 3.7 cm. The breeding season is in spring, depending on the region from February to May, mostly in March or April. The eggs are incubated for 17 to 19 days until the young birds hatch. Only females breed, but both sexes participate in the food supply and defense of the territory. The young birds fledge after 35 days.

The nest of the crow are the cuckoo Indian Koel ( Eudynamys scolopaceus parasitized).

Social behavior

The birds spend the night in large groups (up to thousands of animals) in roosting places. Large groups come to the main sleeping areas, especially at dusk. These sleeping places are almost equally frequented throughout the year and are mainly used by non-breeders.

Taxonomy and subspecies

The big-billed crow belongs to a species complex of species found in East Asia, Australia and Oceania. The early editors such as Richard Meinertzhagen even regarded it only as a form of the Australian New Holland crow Corvus coronoides . In a phylogenomic study of the Corvidae based on homologous sequences of the MtDNA , the brilliant crow was identified as a sister species .

Hybrids have been identified with the carrion crow ( Corvus corone ). At the limit of distribution to the parapatric common raven Corvus corax, there are transition populations with intermediate characteristics, which have been described as subspecies tibetosinensis and intermedius (see below). This could be a hybrid zone of the similar and closely related species, but this has not been genetically proven.

The structure of the widespread species is problematic and has not yet been satisfactorily clarified. Up to 11 subspecies have been described. Of these, one, two, four or seven are recognized by some authors as their own species, while others hold on to subspecies status. A careful overview of all previous species concepts by EC Dickinson and colleagues does not consider a split to be justified at the moment due to too many open questions.

When investigating the calls of big-billed crows in the Indian Himalayas, Jochen Martens and colleagues were able to distinguish two clearly separated groups, one in the higher elevations and spreading in the north and east, which they call japonensis , and one spreading more south and in the lowlands, of called them levaillantii . These forms are recognized by many authors (e.g.) as separate species, calling the northern / eastern form macrorhynchos . Both groups can also be distinguished morphologically, the easiest way to look at the color of the base of the neck feathers, which is white in the northern / eastern forms and gray in the southern / western forms. In Ernst Mayr's view, the nominate form is only common on the Malay Peninsula as far as Timor , so that, according to Dickinson and colleagues, the name should not be used for the animals that are common in the north.

In a genetic examination of animals from Japan and the bordering eastern East Asia (excluding China), an “island group” and a “mainland group”, which also included the animals from the Kyūshū Islands and Taiwan, could be distinguished. The genetic differences were mostly relatively small. The genetic structure can be explained by a settlement of the islands from the mainland. Although the data, also in the opinion of the authors, are not yet sufficient for a taxonomic treatment, they indicate that they would allow the cleavage of the subspecies connectens .

In the following list, all described subspecies that are still used today are taken into account. Most of these are not recognized by all reviewers, and the status of some is very controversial. A detailed taxonomic treatment is not possible at this point.

• Northern and eastern forms ("" macrorhynchos / japonensis ""):
  • Corvus macrorhynchos macrorhynchos Wagler, 1827. Nominate form . southern Malay Peninsula to Timor
  • Corvus macrorhynchos intermedius Adams, 1859. Himalaya, Nepal to Afghanistan.
  • Corvus macrorhynchos tibetosinensis O. Kleinschmidt & Weigold, 1922. Eastern Himalaya, Tibet. also used by some authors for animals from Myanmar .
  • Corvus macrorhynchos philippinus (Bonaparte, 1853). Philippines. Recognized as a species by Avibase
  • Corvus macrorhynchos japonensis Bonaparte, 1850. Japan, Kuril Islands, possibly Sakhalin Island .
  • Corvus macrorhynchos mandshuricus Buturlin, 1913. Russian Far East, Northern China
  • Corvus macrorhynchos colonorum Swinhoe, 1864. Central and southern China including Hainan and Taiwan to northern Indochina
  • Corvus macrorhynchos connectens Stresemann, 1916. The Japanese islands of Amami-Ōshima and northern Ryūkyū islands
  • Corvus macrorhynchos osai Ogawa, 1905. southern Ryūkyū Islands
• Southern and western forms ("levaillantii"):
  • Corvus macrorhynchos levaillantii Lesson , 1831. India, Thailand, Indochina to northern Malay Peninsula. Recognized as a species by Avibase and the IOC World Bird List
  • Corvus macrorhynchos culminatus Sykes, 1832. South India and Sri Lanka (according to some authors, a separate subspecies anthracinus Madarász, 1911). Recognized as a species by Avibase and the IOC World Bird List

Web links

Commons : Corvus macrorhynchos  - collection of images, videos and audio files

• Typical call of several birds ( OGG ; 99 kB)
• Big-billed crow voices (two birds) ( Memento from December 11, 2005 in the Internet Archive ) ( WAV ; 383 kB)
• Big-billed crow videos on the Internet Bird Collection
• Corvus macrorhynchos inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved March 24, 2015.
• Corvus macrorhynchos inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved March 24, 2015.

swell

• Steve Madge : Crows and Jays. Helmet Identification Guides. A&C Black, 2010, ISBN 978-1-4081-3527-3 .
• Richard Porter, Simon Aspinall: Birds of the Middle East. Bloomsbury Publishing, 2013. ISBN 978-1-4081-8122-5
• Mark Brazil : Birds of East Asia. Helm field guides. Bloomsbury Publishing, 2014. ISBN 978-1-4729-0356-3
• Allen Jeyarajasingam: A Field Guide to the Birds of Peninsular Malaysia and Singapore. Oxford University Press, 2012. ISBN 978-0-19-963943-4
• Richard Grimmett, Carol Inskipp, Tim Inskipp: Birds of the Indian Subcontinent. Helm field guides. Bloomsbury Publishing, 2013. ISBN 978-1-4081-6264-4

Individual evidence

1. ↑ Eunok Lee, Jun Miyazaki, Shinya Yoshioka, Hang Lee, Shoei Sugita (2012): The Weak Iridescent Feather Color in the Jungle Crow Corvus macrorhynchos. Ornithological Science 11 (1): 59-64.
2. ^ Colin R. Trainor and Thomas Soares: Birds of Atauro Island, Timor-Leste (East Timor) , Forktail 20 (2004), pp. 41-48
3. ↑ Ann Downer: Wild Animal Neighbors: Sharing Our Urban World. Twenty-First Century Books, 2013. ISBN 978-1-4677-1663-5 . Limited preview on Google Books
4. ↑ ^{a b} Hajime Matsubara (2003): Comparative study of territoriality and habitat use in syntopic Jungle Crow (Corvus macrorhynchos) and Carrion Crow (C. corone). Ornithological Science 2: 103-111.
5. ^ ^{A b c} Whistler, Hugh (1928) Popular Handbook of Indian Birds. Gurney and Jackson .
6. ^ Derek Goodwin : Crows of the World . Queensland University Press, St Lucia, Qld, 1983, ISBN 0-7022-1015-3 .
7. ↑ Elisabeth Haring, Barbara Däubl, Wilhelm Pinsker, Alexey Kryukov Anita Gamauf (2012): Genetic divergences and intraspecific variation in corvids of the genus Corvus (Aves: Passeriformes: Corvidae) - a first survey based on museum specimens. Journal of Zoological Systematics and Evolutionary Research 50: 230-246. doi: 10.1111 / j.1439-0469.2012.00664.x
8. ^ Eugene M. McCarthy: Handbook of Avian Hybrids of the World. Oxford University Press, 2006. ISBN 978-0-19-518323-8 possible hybrid zones: Fig. 13, p. 226
9. ↑ S. Madge (2009): Large-billed Crow (Corvus macrorhynchos). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, DA & de Juana, E. (editors) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (from http://www.hbw.com/node/60796 on March 24, 2015)
10. ^ EC Dickinson, S. Eck, J. Martens (2004): Systematic notes on Asian birds. 44. A preliminary review of the Corvidae. Zoological Negotiations Leiden 350: 85-109.
11. ↑ Jochen Martens, Jörg Böhner, Kurt Hammerschmidt (2000): Calls of the Jungle Crow (Corvus macrorhynchos s. Left) as a taxonomic character. Journal of Ornithology 141: 275-284.
12. ^ Richard Grimmett, Carol Inskipp, Tim Inskipp: Birds of the Indian Subcontinent. Helm field guides. Bloomsbury Publishing, 2013. ISBN 978-1-4081-6264-4
13. ↑ Steve Madge: Crows and Jays. Helmet Identification Guides. A&C Black, 2010. ISBN 978-1-4081-3527-3
14. ^ John Ramsay MacKinnon, John MacKinnon: A Field Guide to the Birds of China. Oxford ornithology series. Oxford University Press, 2000. ISBN 978-0-19-854940-6
15. ↑ In: JK Stanford & E. Mayr (1940): The Vernay Cutting Expedition to Northern Burma. Part I. Ibis 14 (4): 679-711.
16. ↑ Alexey Kryukov, Liudmila Spiridonova, Sumio Nakamura, Elisabeth Haring, Hitoshi Suzuki (2012): Comparative Phylogeography of Two Crow Species: Jungle Crow Corvus macrorhynchos and Carrion Crow Corvus corone. Zoological science 29: 484-492. doi: 10.2108 / zsj.29.484
17. ^ Corvus philippinus at Avibase
18. ^ Corvus levaillantii at Avibase
19. ↑ ^{a b} Crows, mudnesters & birds-of-paradise at IOC World Bird List
20. ↑ Corvus culminatus at Avibase