American Crow
Corvus brachyrhynchos
Summary 6
The American Crow (Corvus brachyrhynchos) is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America. In the interior of the continent south of the Arctic, it is referred to as simply the "crow".
Distribution 7
American crows are native to the Nearctic region all over North America. They can be found in the lower part of Canada and through the continental United States.
Biogeographic Regions: nearctic (Native )
Morphology 8
Adult American crows are completely black birds weighing on average 450 g. The feathers have a glossy and slightly iridescent look. Crows have strong legs and toes. The bill is also black with a slight hook on the end. Stiff bristles cover their nostrils. About 20% of male birds are slightly larger than the females.
Young crows are about the same size as adults, but have blue eyes and pink inside the mouth. Both the eyes and mouth darken as the bird becomes an adult. In young birds, the ends of tail feathers are symmetrical and are more pointed than the wide, flat-ended feathers of adults. The wing and tail feathers of the young can become quite brown and ragged through the first winter and spring and only become darker and more glossy like adult feathers after the first molt.
American crows are often confused with common ravens. American crows can be distinguished from common ravens (Corvus corax) most easily by size (ravens are much larger), by voice (ravens are hoarser), by the bill (ravens have heavier, "roman-nosed" bills), and by the shape of the wings and tails, which come to a point in ravens but not crows.
Average mass: 450 g.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; male larger
Average mass: 384.8 g.
Habitat 9
American crows prefer open areas with nearby trees. Agricultural and grassland areas are ideal habitat for crows to forage for their food. American crows will also use nearby woodlots and forest edges for breeding and roosting. American crows thrive in suburban neighborhoods and urban parks, as well as in coastal habitats.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Aquatic Biomes: coastal
Other Habitat Features: urban ; suburban ; agricultural ; riparian ; estuarine
Migration 10
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Breeding populations north of southern Canada move south for winter.
In Washington, centers of activity of juvenile American crows were 0.2-22.2 km away from the natal territory during their first 3-12 months (Withey and Marzluff 2005).
Sources and Credits
- (c) Anita Gould, some rights reserved (CC BY-NC), uploaded by Anita Gould, http://www.flickr.com/photos/61897811@N00/2470003522
- (c) Walter Siegmund, some rights reserved (CC BY-SA), https://upload.wikimedia.org/wikipedia/commons/c/c2/Corvus_brachyrhynchos_30186.JPG
- (c) steven_bach, some rights reserved (CC BY-NC-SA), http://farm9.staticflickr.com/8343/8226941927_276d07fd34_o.jpg
- (c) steven_bach, some rights reserved (CC BY-NC-SA), http://farm9.staticflickr.com/8060/8228010088_ec29dc0a44_o.jpg
- (c) hobiecat, some rights reserved (CC BY-NC), uploaded by hobiecat
- (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Corvus_brachyrhynchos
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31387593
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31387595
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/31387594
- (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/28846805
