American Crow

SCIENTIFIC NAME: Corvus brachyrhynchos

OTHER NAMES: Common crow

DESCRIPTION: At 17 to 21 inches, Corvus brachyrhynchos is the largest of the three subspecies of crow found in North America. The two smaller subspecies, the northwestern (Corvus caurinus) and fish crow (Corvus ossifragus) are typically found near the shore. Due to similar appearance, the American crow can be mistaken for a raven. However, ravens are typically larger in size and have a wedge-shaped tail. Crows have a slight hook on the end of the black bill, and strong black legs and feet. Their rounded wings, tail, and glossy black appearance distinguish them from ravens. The call is easily recognizable as a loud, carrying "caw, caw, caw.” The male and female are similar in appearance and voice. Young crows are similar in size to the adult but have blue eyes and pink inside the mouth. The wings and tail feathers of the young can become brown and ragged through their first winter and spring, and then become darker like the adult after their first molt.

DISTRIBUTION: Corvus brachyrhynchos breeds from central Canada south to California, Florida, and Texas. American crows are abundant in the eastern United States, uncommon and very local in the Far West, and less populated in the treeless plains states. The American crow is very common in Alabama, making short migrations from states just to our north to over winter. Alabama also has a large native breeding population which remains year round.

HABITAT: Crows utilize virtually any habitat including forests, wood lots, open areas, farmlands and suburbs. They can be found near the shore as well as in the mountains. They prefer open areas with nearby woodlots and forest edges for breeding, roosting, and foraging. Agricultural and grassland areas are ideal habitat for foraging. Crows thrive in suburban neighborhoods and urban parks.

BEHAVIOR & FEEDING HABITS: Hunting in "mobs," crows are omnivores and will feed on carrion anywhere they find it. Crows defend large all-purpose territories. Robbing nests of eggs and small birds is not uncommon. Small grains such as corn and wheat are a favorite food source.  Crows are known to hide food in short-term caches and will hide meat, nuts, and seeds in tree crevices or on the ground until they are ready to eat.  They use the beak to hammer open nuts or may carry them high in the air and drop them on hard surfaces to break open the hard shells. Large numbers of crows, from tens to hundreds of thousands, will assemble in the late afternoon in areas of large trees, and then move to a final roosting site for the night. In addition to family and winter roost groups, crows form what is known as "floater" groups. These flock participants probably lack mates. Some of these individuals spend time in the natal territories as helpers. American crows engage in a behavior called anting. A crow will position itself over an anthill and allow ants to scramble among its feathers, or it may pick up single ants or small groups and rub them into its feathers.  

BREEDING: Crows are cooperative breeders, which means both the male and female as well as younger siblings will help raise and protect their young. Maturity in male crows is not reached until their second year. Breeding may begin as early as February and last through June. Nests are built by the male and female, usually high in a large conifer or hardwood tree. Females lay four to five light green  eggs with brown markings. The female incubates the eggs which hatch in 18 days. While nesting, the female will beg for food like a baby bird, and her mate will bring it to her. Baby crows are helpless at birth and require parental care. They are nurtured by both parents as well as helpers who are their older siblings. The young fledge (leave the nest) when they are approximately 35 days old. Adult crows have been observed feeding young even after they have left the nest and are capable of foraging for themselves.  

LIFE HISTORY AND ECOLOGY: Crows are members of the family Corvidae and are related to blue jays, magpies, and nutcrackers. They are considered to be highly intelligent and creative species.  Although it is illegal to possess a crow as a pet, captive crows have been known to mimic human speech. The oldest recorded age of a wild American crow is 14 years and seven months. Large foraging flocks may have a negative impact on agriculture, particularly orchards and cornfields. There once was a bounty on them. American crows are a known carrier of West Nile Virus and are more susceptible to death by the virus than other species. They may have a positive impact by eating insects which would have a negative impact on agriculture. In Alabama, crows are hunted as a small game animal for recreation and sport when more desirable game bird species cannot be hunted.

REFERENCES:

Yaremych SA, West Nile Virus and high death rate in American Crows. www.cdc.gov

Parr, C. 2005. "Corvus brachyrhynchos" (On-line), Animal diversity Web. At animaldiversity.ummz.umich.edu

Griscom, Ludlow. 1950. Audubon's Birds of America. The Macmillan Co., New York, N.Y. 245pp.

Bruun, Beretel. 1974. The Dell Encyclopedia of Birds. Delacorte Press. Dell Publishing Co., New York, N.Y. 47pp.

Wernert, Susan J., Reader's Digest North American Wildlife. Reader"s Digest Association, Pleasantville, N. Y. 1982. 125pp.

Author: Stuart Goldsby, Division of Wildlife and Freshwater Fisheries