American Crow (Corvus brachyrhynchos): Facts and Intelligence

Appearance and how to recognize it

Everything about an American crow is black: the plumage, bill, legs, feet and eyes. In good light the feathers shine with a blue or purple gloss. Males and females look alike, though males are slightly larger on average. Young crows in their first months have blue-gray eyes and a pink mouth lining, which darken as they mature, and their wing and tail feathers often look brownish and worn by their first spring.

The bill is strong and straight, with stiff bristles covering the nostrils. In flight the tail looks short and squared or gently rounded, like a fan, and the wingbeats are steady and rowing. Crows rarely glide for long.

Three similar birds cause confusion. The common raven is much bigger, with a wedge-shaped tail, a heavier bill and a deep croaking voice; see crow vs raven for a full guide. The fish crow (Corvus ossifragus) of the eastern and southern United States is slightly smaller and is best told by its nasal “uh-uh” call. In the Pacific Northwest, the former northwestern crow, once treated as a separate species, was merged into the American crow by the American Ornithological Society in 2020.

Size: how big is an American crow?

American crows measure 40–53 cm (16–21 in) from bill tip to tail tip, about 40% of which is tail. The wingspan is 85–100 cm (33–39 in), and adults weigh 316–620 g (11–22 oz), with an average close to 450 g (1 lb).

Size changes across the continent. The largest crows live in the Northeast and eastern Canada, while those of the far West and the southern coast are smaller, with slimmer bills. Scientists usually recognize three to five subspecies, but the differences between them are gradual.

Habitat and range

American crows live from the Pacific to the Atlantic in southern Canada, across nearly the whole of the United States and into northern Mexico. They are missing only from the Arctic tundra, and they are scarce in the hottest, driest deserts of the Southwest.

Their favorite habitat is open ground for feeding with tall trees nearby for nesting and roosting: farmland, pastures, riverside woods, forest edges, parks, golf courses and suburbs. Over the last century they have moved steadily into towns and cities, where food is plentiful and shooting is rare. Most crows in the United States stay in the same area all year, while many from Canada and the northern Great Plains move south for the winter.

Diet: what do American crows eat?

The American crow is a true omnivore. It walks across fields and lawns picking up earthworms, beetles, grasshoppers and caterpillars, and it eats grain, seeds, acorns, walnuts, fruit and berries. It also takes eggs and nestlings from other birds’ nests, catches mice, frogs and other small animals, scavenges road-killed animals and stranded fish, and visits trash cans and landfills.

Crows show real ingenuity when feeding. They hold a nut under one foot and hammer it with the bill, and they fly up with walnuts or clams and drop them onto roads or rocks to crack them. They also hide spare food in scattered caches, in tree crevices or under leaves, and return to it later. Insect-eating in summer helps farmers, though flocks can also damage corn and orchard crops.

Family life and behavior

American crows are cooperative breeders, a rare system among North American birds. A breeding pair defends a territory year-round, and young crows often stay with their parents for one to several years, helping to feed the next broods and to chase away predators. Families can grow to as many as 15 birds from several years.

Crows are loud and social. Family members preen each other, call to warn of danger and gang up to mob hawks, owls and cats, diving and cawing until the predator leaves. They also practice “anting,” letting ants crawl through their feathers or rubbing ants on their plumage, possibly to deter parasites.

From fall to late winter, thousands of crows gather each evening at communal night roosts, often in towns. Read more in Why do crows gather in huge flocks?

Calls and communication

The best-known sound is the loud, harsh “caw,” often given in rhythmic series while the bird bobs its head. Short, sharp caws signal alarm, longer series are used in territorial exchanges with neighbors, and harsh, rapid cawing accompanies mobbing.

Crows have a much larger vocabulary than most people realize. They give rattles, clicks and soft, musical coos between family members, and young birds make gurgling begging calls. Crows can also mimic other sounds, including the calls of other birds such as the barred owl.

Intelligence

Crows belong to the corvid family, which also includes ravens, magpies and jays and is famous for brainpower. American crows modify and use simple tools, solve puzzles, remember where they hid food and learn from one another.

Their most famous skill is recognizing individual people. In experiments at the University of Washington, crows learned to scold researchers who had trapped them while wearing a particular mask, and the reaction spread to crows that were never caught. See Do crows remember faces? and How smart are crows and ravens? for the details.

Reproduction and life cycle

Most American crows do not breed until they are at least two years old, and many wait until four or five while they help their parents. Nesting starts between February and April. Both partners build a bulky nest of sticks lined with bark, grass and fur, usually high in a tree, often an oak or a conifer.

The female lays 3–6 pale bluish-green eggs with brown blotches and incubates them for about 18 days, while her mate and helpers bring her food. The chicks are naked and helpless at hatching and leave the nest at about 35–36 days old. They still depend on the family for weeks afterward, begging noisily through the summer. Pairs usually raise one brood a year.

Lifespan, predators and threats

Wild American crows live about 7–8 years on average, although first-year mortality is high. Banded wild birds have lived more than 14 years, and captive crows have reached about 30.

Eggs and chicks are taken by raccoons, snakes, ravens, domestic cats and other nest robbers. Adults have fewer enemies: great horned owls, which raid roosts and nests at night, red-tailed hawks, peregrine falcons and eagles.

The biggest modern threat has been West Nile virus, which arrived in North America in 1999. American crows are extremely vulnerable to it, and local populations fell sharply in some areas, with an overall decline estimated at up to 45%. Because sick crows are easy to notice, health agencies used them as an early warning sign of the virus. Crows cannot pass the virus directly to people; it spreads through mosquito bites.

Conservation status

The American crow is listed as Least Concern on the IUCN Red List. BirdLife International estimated the population at around 31 million birds in 2012, and the species has adapted well to farming and urban life.

That success came despite a long history of persecution. In the early 20th century, crows were treated as farm pests, and some states even used explosives to destroy roosts, with little effect on overall numbers. Today crows are protected in the United States under the Migratory Bird Treaty Act.

Myths and facts

Myth: a crow is just a small raven. Crows and ravens are separate species in the same genus, Corvus. The common raven is roughly twice as heavy as an American crow and differs in tail shape, voice and behavior.

Myth: a crowd of crows means something has died. The name “a murder of crows” comes from old folklore, not from crow behavior. Large gatherings are usually winter roosts, feeding flocks or groups mobbing a predator. Crows do gather noisily around a dead crow, but research suggests they are learning about danger rather than mourning; see What is a group of crows called?

Fact: crows are songbirds. Despite their harsh voices, crows belong to the order Passeriformes, the perching birds, and the same suborder as thrushes and warblers. They are among the largest members of that group.

Fact: crows can live in families for years. Unlike most songbirds, whose young leave within weeks, American crow offspring often stay home for several years and help raise their younger siblings.

Crows and people

Crows have lived alongside people for thousands of years, and few wild birds provoke stronger feelings. Their black plumage and habit of eating carrion linked them to death and bad omens in European folklore, while many Indigenous North American traditions see the crow as a clever trickster or culture hero.

Crows also feature in Aesop’s fables such as “The Crow and the Pitcher,” in which a thirsty crow drops pebbles into a jug to raise the water level, a story that modern experiments have shown is not far from what some corvids can actually do.

In spring, some crows dive at people who walk too close to their fledglings, which have just left the nest and spend several days on or near the ground. The swoops are a warning rather than an attack, and the best response is simply to give the young birds space for a few days.