and see text The American coot (Fulica americana), also known as a mud hen or pouldeau, is a bird of the family Rallidae.

Unlike the webbed feet of ducks, coots have broad, lobed scales on their lower legs and toes that fold back with each step to facilitate walking on dry land.

It lives in the Pacific and southwestern United States and Mexico year-round and occupies more northeastern regions during the summer breeding season.

[4] American coots eat primarily algae and other aquatic plants but also animals (both vertebrates and invertebrates) when available.

[citation needed] Eurasian coots can be distinguished from this species by the absence of a red callus above the bird's frontal shield.

[8] The American coot was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[9] Gmelin based his description on the "Cinereous coot" from North America that had been described in 1785 by the English ornithologist John Latham in his book A General Synopsis of Birds.

[14] Thus, it seems that the modern-type American coots evolved during the mid-late Pleistocene, a few hundred thousand years ago.

[5] The American coot is recognized by its white frontal shield with a red spot connecting its eyes.

[5] American coots are found near water reed-ringed lakes and ponds, open marshes, and sluggish rivers.

[20][21] Autumn migration occurs from August to December, with males and non-breeders moving south before the females and juveniles.

Spring migration to breeding ranges occurs from late February to mid-May, with males and older birds moving North first.

[25] When swimming on the water surface, American coots exhibit a variety of interesting collective formations, including single-file lines, high density synchronized swimming and rotational dynamics, broad arcing formations, and sequential take-off dynamics.

During breeding season, coots are more likely to eat aquatic insects and mollusks—which constitute the majority of a chick's diet.

A typical reproductive cycle involves multiple stages: pairing, nesting, copulation, egg deposition, incubation, and hatching.

[28] The American coot is a prolific builder and will create multiple structures during a single breeding season.

Since American coots build on the water, their structures disintegrate easily and have short life spans.

Egg and brood nests are actually elaborate rafts, and must be constantly added to in order to stay afloat.

It is possible to induce a female coot to lay more eggs than normal by either removing all or part of her clutch.

[30] The American coot is a persistent re-nester, and will replace lost clutches with new ones within two days of clutch-loss during deposition.

Brood size limits incubation time, and when a certain number of chicks have hatched the remaining eggs are abandoned.

These additional offspring, however, suffer higher mortality rates due to inadequacy in brooding or feeding ability.

[34] Hormones that are passed down from the mother into the egg affect offspring growth, behavior, and social interactions.

[36] Increasing reproductive success under social and ecological constraints is the primary reason for brood parasitism.

[8] Parents aggressively reject parasite chicks by pecking them vigorously, drowning them, preventing them from entering the nest, etc.

[8] Chick recognition reduces the costs associated with parasitism, and coots are one of only three bird species in which this behavior has evolved.

The first evidence for parental selection of exaggerated, ornamental traits in offspring was found in American coots.

This brightly colored, exaggerated trait makes coot chicks more susceptible to predation and does not aid in thermoregulation, but remains selected for by parental choice.

Conversely, the bold behavior of immature and adult coots leads to them falling prey with relative regularity once out of the breeding season.

They are rarely the targets of hunters since their meat is not considered to be as good as that of ducks; although some are shot for sport, particularly in the southeastern United States.