The waterborne American coot has a small head and thin legs. Its dark body and white face is a common sight on nearly any open water throughout the continent, often mixing with ducks. Despite this, they are closer relatives of the Long-legged sandhill crane and the almost invisible rails than of teal or mallards.
In summer, American coots are found in New York and Massachusetts in the northern United States, and in southern Canada. During winter, they occur in the southern United States from Florida to California. Individuals have been sighted as far as Alaska in the north and South America in the south, always along waterways. Being freshwater birds, they live in the shallow parts of freshwater ponds, lakes, or marshes, and sometimes in brackish water. They occasionally live in manmade ponds in parks and golf courses.
American coots are diurnal social birds that live in flocks, and are the only rail family members to live in groups. These birds can make a wide range of noises, from clucking to grunting, to communicate with each other and also to threaten predators. On two occasions a coot will splash: in the mating season for the purpose of attracting attention, and also to discourage predators. Ospreys (a type of hawk) are their main predator. Since this species is more adapted to living on water than other birds, it is not possible for them to take off from a "dead start" like other birds, which can take flight when startled. Instead, in order to become airborne, they need to take a running start over the water. American coots are migratory, and they migrate as a flock, but their migration is weather-based and therefore is highly irregular.
An American coot is omnivorous and eats invertebrates, algae, plants, and small vertebrates such as fish and tadpoles, occasionally, eggs of other marsh birds, also sometimes stealing food from ducks.
American coots are monogamous and pairs stay together for life. The mating process starts with great show. Male and female both start off displaying in front of each other and calling to one another, while they splash about. The mating process starts on the water and finishes on the land. Breeding occurs around May and June. Both adults construct a nest of about 35cm across. Nests are at the edge of reed cover at the pond’s edge. They have a ramp leading into the water for easier access for the young. 8 to 10 pink eggs with brown spots are laid at a time. Both parents incubate the eggs, for around 21 to 25 days. They share the tasks of feeding and teaching the young, dividing the hatchlings between them. After a month, young can dive for food, and when they are 5 to 6 weeks old they can fly, becoming fully independent at about 2 months.
Although now widespread and abundant, the American coot suffered huge declines during the late 18th century and the early 19th century due to hunting and loss of wetland in its main breeding areas in the mid-west of the United States and in east-central Canada. This species in some areas is now regarded as an agricultural pest, such as on golf courses and in rice fields, and, being a listed game bird, about 8,000 are killed each year in Canada and about 880,000 in the United States.
According to the IUCN Red List, the total American coot population size is estimated at 6 million individuals. Currently this species is classified as Least Concern (LC), but its numbers today are decreasing.
American coots affect the populations of aquatic plants and invertebrates that they eat. They also serve as prey for predators which share their habitats.