American crow

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American crow
American crow (Corvus brachyrhynchos) calling? / I

American crow ( Corvus brachyrhynchos ) reputation ? / i
Audio file / audio sample

Systematics
Order : Passerines (Passeriformes)
Subordination : Songbirds (passeri)
Superfamily : Corvoidea
Family : Corvids (Corvidae)
Genre : Ravens and Crows ( Corvus )
Type : American crow
Scientific name
Corvus brachyrhynchos
Brehm , 1822
Distribution area
An egg from an American crow

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

Commons : American Crow  - Album with pictures, videos and audio files

Individual evidence

  1. ↑ Corvus brachyrhynchos in the endangered Red List species the IUCN 2016 Posted by: BirdLife International, 2016. Retrieved on October 10, 2017th
  2. ↑ a b c d e f Steve Madge u. a., p. 152
  3. ↑ a b c d Steve Madge u. a., p. 153
  4. ^ Robert Ridgway, p. 362
  5. ^ Samuel Elliott Coues, p. 84
  6. ↑ Allan Robert Phillips, p. 574