The American crow (Corvus brachyrhynchos) is a large passerine bird species of the family Corvidae. American crows are the New World counterparts to the Carrion crow and the hooded crow. Although the American crow and the hooded crow are very similar in size, structure, and behavior, their calls and visual appearance are different. The American crow, nevertheless, occupies the same ecological niche that the Hooded crow and Carrion crow do in Eurasia. They are very intelligent, and adaptable to human environments.
The feathers of the American crow are shiny and varicolored while their bills are black, solid, and strongly bent backward in the end. Nostrils are covered with rough and stiff plumage. Young and adult crows are the same size, though the eyes of the young are blue and their mouths are pink inside. With growing up their eyes and mouths become darker. Young birds are also identified by the sharpened, symmetric end of their tails while adults’ feathers on the end of their tails are wide open and rounded. In addition, during the first winter and spring of their lives, the wings and tails of youngsters are irregularly covered with brown-colored feathers. And then, when the first molt happens, newly growing hair is darker and shiny, thus giving the young appearance of adults.
American crows’ habitat covers a vast territory. In Canada, it stretches from the Atlantic to the Pacific Ocean. It also includes northern regions of Mexico, southern states of the US, and overseas territories of France - St-Pierre, and Miquelon. Crows live in areas with open views and trees. Being robbers, crows find farms and meadows as suitable places for living and raiding for food. Crows also find forest areas and especially edges of forests perfect for breeding or just sitting on branches. They can be found in city parks, suburbs of large cities as well as along the seashore.
American crows are very sociable birds, usually joining small groups made up of families. As a regular rule, all their lives they live in the same place, being permanent residents of the area, defending the home range, and growing up young. However, as autumn comes, some crows migrate from northern regions to the south. Outside of the nesting season these birds often gather in large (thousands or even millions) communal roosts at night. American crows are diurnal. They congregate at dusk on trees and fly to the place of roosting. Along with flying, they often walk on branches of trees and on the ground. American crows usually search for food on the ground: they walk around, looking for suitable items and picking. To feed, they can make up small groups of a few individuals. However, when foraging, they can congregate into larger groups in larger areas.
American crows are omnivorous, meaning that they eat the food of both plant and animal origin. During spring and summer seasons they feed upon worms, larvae, and insects as well as corn, fruits, and nuts. In autumn and winter, they eat acorns, nuts, and walnuts. Crows also enjoy preying on small rabbits, frogs, and mice. On the other hand, being nest predators, they feed on eggs. Crows that live in close proximity to human settlements, look for food in the trash and feed upon animals hit by cars.
American crows are monogamous. Mated pairs cooperate, forming big groups of around 15 birds from different breeding seasons. They stay and live together as families. Planning to have chicks, a male and a female start building a nest, making it of bark, branches of trees, sticks, vegetable fibers, and other available material. The season of nesting takes place quite early. For example, some individuals of American crows start incubating eggs in April. Thus, females lay 4-5 eggs, incubating them for around 18 days. Chicks, hatching, are altricial and require care and feeding by parents. Parents feed the chicks by regurgitating food into their mouths. Feathers start to appear 35 days after their hatching out of eggs. A month later the chicks are able to leave, but parents don’t allow them to, feeding and caring for them throughout another month. American crows reach their reproductive maturity at the age of 3 years.
In spite of being protected, hunting season in the USA affects the crows along with many other animals. Unfortunately, a huge number of American crows are killed for entertainment purposes, for sporting (when hunting other birds is prohibited by law), and during campaigns, having the goal to reduce crows’ population.
BirdLife International, the world’s largest nature conservation partnership, notes that the estimated population of the American craw reaches up to 31 million. According to IUCN Red List, the American crow is widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List, and its numbers today are increasing.
Feeding on fruit and nuts, the crows unconsciously become dispersers of seeds. They also contribute to the decay of corpses and carcasses by pecking them.