The American robin is a migratory songbird that is widely distributed throughout North America and Central America. It has a brown back and a reddish-orange breast, varying from a rich red maroon to peachy orange. The head varies from jet black to gray, with white eye arcs and the throat is white with black streaks. Its belly and undertail coverts are white. The bill is mainly yellow with a variably dark tip, the dusky area becoming more extensive in winter, and the legs and feet are brown. The male and the female are similar, but the female tends to be duller than the male, with a brown tint to the head, brown upperparts, and less-bright underparts. The juvenile is paler in color than the adult male and has dark spots on its breast and whitish wing coverts.
American robins breed throughout most of North America, from Alaska and Canada southward to northern Florida and Mexico. While some birds occasionally overwinter in the northern part of the United States and southern Canada, most migrate to winter south of Canada from Florida and the Gulf Coast to central Mexico, as well as along the Pacific Coast. American robins inhabit dense forests, woodlands, tundra, shrubland, and more open farmland. They are also common in gardens, orchards, and city parks.
American robins are active mostly during the day, and on their winter grounds, they assemble in large flocks at night to roost in trees in secluded swamps or dense vegetation. The flocks break up during the day when the birds feed on fruits and berries in smaller groups. During the summer, American robins defend their breeding territory and are less social. These birds forage primarily on the ground for soft-bodied invertebrates, and find worms by sight (and sometimes by hearing), pouncing on them and then pulling them up. They are frequently seen running across lawns picking up earthworms, and their running and stopping behavior is a distinguishing characteristic. American robins are often among the first songbirds singing as dawn rises or hours before, and last as evening sets in. They usually sing from a high perch in a tree. Males have a complex and almost continuous song that is commonly described as a 'cheerily' carol. American robins also communicate with various calls used in specific situations; when a ground predator approaches and when a nest or another American robin is being directly threatened. Even during nesting season, when these birds become very territorial, they may still band together to drive away a predator.
American robins are omnivores. They feed on small invertebrates (mainly insects), such as earthworms, beetle grubs, caterpillars and grasshoppers, and wild and cultivated fruits and berries. Nestlings are fed mainly on earthworms and other soft-bodied animal prey. In some areas, robins feed on beaches, taking insects and small mollusks.
American robins are serially monogamous and usually form pair bonds that last only during one breeding season. They begin to breed shortly after returning to their summer range. They normally have 2 to 3 broods per breeding season, which lasts from April to July. Their nest is most commonly located 1.5-4.5 m (4.9-14.8 ft) above the ground in a dense bush or in a fork between two tree branches and is built by the female alone. The outer foundation consists of long coarse grass, twigs, paper, and feathers. This is lined with smeared mud and cushioned with fine grass or other soft materials. A new nest is built for each brood. The female lays 3 to 5 light blue eggs and incubates them alone for about 14 days. The chicks are altricial; they are hatched blind and naked. While the chicks are still young, the mother broods them continuously. When they are older, the mother will brood them only at night or during bad weather. The chicks leave the nest 2 weeks after hatching, however, they still follow their parents around begging for food. After leaving the nest the fledglings are able to fly short distances and it only takes a couple of weeks for them to become proficient at flying.
American robins are abundant and widespread throughout their range, however, they are vulnerable to pesticide poisoning, climate changes, severe weather, and predation.
According to the What Bird resource, the total population size of the American robin is around 320 million birds. According to the All About Birds resource the total breeding population size of this species is 310 million breeding birds. Overall, currently, American robins are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.
American robins control insect populations and disperse the seeds of the fruits they eat. They also serve as an important food source to local predators including squirrels, snakes, crows, cats, foxes, dogs, raccoons, weasels, and especially raptors.