American crow
American crow | ||||||||||||
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American crow ( Corvus brachyrhynchos ) |
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Systematics | ||||||||||||
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Scientific name | ||||||||||||
Corvus brachyrhynchos | ||||||||||||
Brehm , 1822 |
The American Crow ( Corvus brachyrhynchos ) is a bird art from the family of corvids (Corvidae). The population of the species was classified in the IUCN's Red List of Threatened Species in 2016 as “ Least Concern (LC) ” = “not endangered”.
features
The 39-49 cm long American crow has shiny, black plumage that sometimes shimmers purple or blue, and blue-green on the wings. The long, broad wings, large beak, and feet are also black. The tip of the tail is rounded. The iris is dark brown. The call is a croaking "Kaa".
In young birds , the iris is initially blue-gray, but turns brown at an early age. At first, the plumage appears more dull than in adult animals. There is no noticeable gender dimorphism .
Occurrence
The distribution area extends in the north from British Columbia to Newfoundland and in the south from California to Florida . The bird lives in prairies , in sparse forests, in fields, on the outskirts and in urban areas. From the northern range it migrates southwards in winter, otherwise it is a resident bird .
food
The diet ranges from invertebrates, carrion, seeds, dead fish, eggs and juveniles of other bird species to crops and discarded fast food. The American crows look for food in large swarms on garbage dumps.
behavior
The American crow mostly breeds individually. Outside the breeding season, millions of birds sometimes gather in the evening and disperse in the morning to forage. They have a well-developed social structure and well-developed communication strategies with which they can describe other feeding places or warn of dangers.
Reproduction
The female lays three to six eggs in a bowl-shaped nest on trees. The young birds hatch after 17 days of breeding and leave the nest after 5 weeks. The young often stay with the family and help raise other offspring.
Subspecies
Four subspecies have been described, which differ in their size and range:
- Corvus brachyrhynchos brachyrhynchos Brehm , 1822; Nominate form : occurs from southern Canada over the southwest of the USA and along the Atlantic coast of Newfoundland .
- Corvus brachyrhynchos hesperis Ridgway , 1887 tends to be slightly smaller than the nominate form and has a thinner beak. It is widespread from the southwest of Canada to the extreme northwest of Mexico.
- Corvus brachyrhynchos pascuus Coues , 1899 is slightly smaller than the nominate form, but has a relatively stronger beak. It only occurs in Florida.
- Corvus brachyrhynchos hargravei Phillips, AR , 1942: about the same size as C. b. pascuus with a relatively smaller beak. This subspecies is found in the southern United States.
literature
- Steve Madge , Hilary Burn: Crows and Jays: A Guide to the Crows, Jays and Magpies of the World . A&C Black Publishers Ltd, London 1994, ISBN 978-0-7136-3999-5 .
- Robert Ridgway: A manual of North American birds . JB Lippincott, Philadelphia 1887 ( online [accessed October 5, 2011]).
- Samuel Elliott Coues: The Finishing Stroke to Bartram . In: The Auk . tape 16 , no. 1 , 1899, p. 83–84 ( online (PDF; 109 kB) [accessed January 12, 2012]).
- Allan Robert Phillips: A new crow from Arizona . In: The Auk . tape 59 , no. 4 , 1942, pp. 573-575 ( online (PDF; 189 kB) [accessed January 12, 2012]).
Web links
- Corvus brachyrhynchos in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed on December 19 of 2008.
- BirdLife International: Species Factsheet - American Crow ( Corvus brachyrhynchos ) . Retrieved January 12, 2012.
- Videos, photos and sound recordings of Corvus brachyrhynchos in the Internet Bird Collection
- American crow ( Corvus brachyrhynchos ) at Avibase; Retrieved January 12, 2012.
- Corvus brachyrhynchos in the Integrated Taxonomic Information System (ITIS). Retrieved January 12, 2012.
- xeno-canto: Sound recordings - American Crow ( Corvus brachyrhynchos )
- Voice of the American crow ( WAV ; 73 kB)
Individual evidence
- ↑ Corvus brachyrhynchos in the endangered Red List species the IUCN 2016 Posted by: BirdLife International, 2016. Retrieved on October 10, 2017th
- ↑ a b c d e f Steve Madge u. a., p. 152
- ↑ a b c d Steve Madge u. a., p. 153
- ^ Robert Ridgway, p. 362
- ^ Samuel Elliott Coues, p. 84
- ↑ Allan Robert Phillips, p. 574