American Coot
The American Coot is a fairly large, duck-like waterbird with short wings and a short tail. It has a length of approximately 12 inches and a wingspan of approximately 25 inches.
The male and female American Coots look similar. They have a white bill with a dark reddish ring just before the tip and a white frontal shield with a reddish oval near the tip. The head, neck, back, upperwings, breast and belly of the American coot are slate gray. It also has a white undertail covert which is exposed as the American Coot walks, flicking and cocking its short tail.
The juvenile American Coot lacks the frontal shield of the adult and has a horn-colored bill possibly lacking the ring at the tip. Its head, neck, upperwings, breast and back are a pale gray-brown and feathers on underparts often have paler edges.
The American Coot may look similar to a duck at first glance but is actually quite different. It has a triangle chicken-like bill instead of the flat bill of ducks and has lobed toes instead of fully webbed feet.
The
American Coot is conspicuous, noisy, and aggressively territorial. They select
from a repertoire of some 14 displays to communicate among themselves. To signal
their social intentions coots vary body postures, adjust the position of the
white undertail coverts, alter the degree to which they arch the wings over the
back, change the angle of erect neck feathers and, when aroused, swell the
frontal "nose" shield.
Many coot displays are associated with strident, year-long territorial defense. Generally, it is the male that confronts perceived threats. When the male partner is absent however, the female becomes demonstrative, reacting first to intruding females before confronting intruding males.
When
an intruder appears, the resident approaches it by modifying its normal slow
paddling into a hastened patrol swim and then makes a wake-forming charge that
may end in a splattering, rapid run across the surface. Such confrontations may
lead to combat. While fighting, a coot usually sits back on the water and grabs
its opponent with one long-clawed foot while attempting to slap the contender
with the free one and jab it with its bill. Apparently, the aim is to push the
opponent onto its back and, in some cases, hold it underwater. Quite impressive,
this sequence can be seen in coots four days old.
Coots
select breeding areas rich in nesting materials and build up to nine bulky,
floating structures. They lay eggs in only one or two of them; the others are
used for displaying, copulating, or brooding. Since incubation is not initiated
until the fourth or fifth egg is laid, ample time is available beforehand for
other birds to parasitize the clutch.
But,
American Coots, unlike the even more aggressive South American Red-fronted
Coots, rarely host the eggs of other species. The mechanism is yet uncertain but
it seems that American Coots have evolved a way to circumvent brood parasitism
that involves neither the vigilance nor the concerted effort seen in many other
species.
Coots
are among the least graceful of marsh birds. Commonly called "splatterers,"
they scramble across the surface of the water with wings flapping not only to
confront intruders but also to become airborne.
Coots
bob their heads while walking, quite likely because the head movements help them
to judge the distance to their prey. While foraging on insects, they bob
quickly; while eating greens, they bob slowly. Appearing somewhat like aquatic
pigeons, coots also bob their heads while swimming.