American crow

American crows live in Canada, the United States and Mexico.

They live near people, in towns, parks and farms. They like open places with a few trees.

American crows live across much of North America, in Canada, the United States and Mexico. They are common almost everywhere in the lower 48 states except the southwestern deserts.

Crows like open places with a few trees to perch in and plenty of food: farms, pastures, beaches, riverbanks, golf courses, parks, yards and even parking lots. They tend to avoid large, unbroken forests and deserts.

The IUCN (2018) lists Canada, the United States, Mexico and Saint Pierre and Miquelon as range countries. The Cornell Lab of Ornithology describes the species as fairly common throughout most of the lower 48 states outside the southwestern deserts.

It is highly adaptable, living in any open place that offers a few trees for perching and a reliable food source, from farmland, pasture and landfills to city parks, cemeteries, vacant lots and the shores of rivers, marshes and beaches. It avoids unbroken forest, though it follows roads and rivers into forests and visits campgrounds.

Crows eat almost anything.

They eat worms, bugs, seeds, nuts and fruit. They also find food that people drop or throw away.

American crows will eat almost anything. They find most of their food on the ground: earthworms, insects, mice, seeds, grains, nuts, fruit and berries. Near water they catch fish, crayfish, young turtles and clams. They also eat garbage and sometimes take eggs and chicks from other birds' nests.

Crows are crafty. They have been seen following birds to find hidden nests, and one group of crows distracted a river otter to steal its fish.

The Cornell Lab of Ornithology describes a very broad diet: grains, seeds, nuts, fruit and berries; earthworms, mice and many insects, including some crop pests; aquatic prey such as fish, young turtles, crayfish, mussels and clams; eggs and nestlings of many birds; carrion; and garbage.

Carrion is a small part of the diet: a crow's bill cannot break the skin of even a gray squirrel, so it must wait for a carcass to be opened or soften. Foraging is opportunistic and often social, including documented cases of crows distracting a river otter to steal its fish and following mergansers to catch minnows driven into the shallows.

Crows are very smart.

Scientists found that crows can remember a person's face for years. Crows also work together to chase away animals that might hurt them.

In 2006, scientist John Marzluff and his students at the University of Washington wore rubber masks while they caught and banded wild crows. Later they walked by wearing different masks. The crows ignored the other masks, but scolded and mobbed the one worn during banding, no matter who wore it.

Years later, those crows were still scolding that mask, and more crows had joined in, including young crows that had never seen the banding. Crows also work together to chase off predators, and in winter thousands sleep together in roosts.

Marzluff's team at the University of Washington tested face recognition by trapping and banding crows while wearing a particular rubber mask, then walking through the same sites in several masks. Crows scolded and mobbed only the banding mask, regardless of clothing or wearer. Nearly seven years later, the proportion of crows mobbing it had roughly doubled, including many birds that were never banded and some born after the experiment began (National Wildlife Federation, 2013). Marzluff suspects that telling people apart helps explain why crows thrive in cities.

The Cornell Lab of Ornithology describes cooperative mobbing of predators and winter roosts of a few hundred to as many as two million crows, some used for more than 100 years. In some areas crows lead a double life: a family territory by day and a huge communal roost at night.

There are lots of American crows.

A sickness called West Nile virus has made many crows sick. Scientists keep counting crows to see how they are doing.

American crows are common: Partners in Flight estimates about 28 million breeding birds. Their numbers dropped slightly between 1966 and 2019, but they are not in danger.

Crows have one big problem: West Nile virus, a disease that arrived in North America in 1999. Crows catch it very easily, and almost all crows that catch it die. In some places many crows were lost. Living close to people brings other challenges too, like noisy roosts in cities.

BirdLife International's 2018 assessment for the IUCN Red List lists the species as Least Concern. The North American Breeding Bird Survey shows a slight decline from 1966 to 2019; Partners in Flight estimates a global breeding population of 28 million and a Continental Concern Score of 6 out of 20, indicating low conservation concern.

The main documented threat is West Nile virus, introduced to North America in 1999. The Cornell Lab of Ornithology notes that virtually all crows that contract it die within a week, that no other North American bird died at the same rate, and that losses were severe in some areas. Urban roosts can also bring conflict with people over noise and mess.