The “All” American Coot
by John Hughes
The American Coot, Fulica americana, (Fulica from Latin meaning “coot”) is truly the “All” American Coot. While conventional range maps indicate the absence of Coots in some states in the northeast and Alaska, an examination of eBird’s range map confirms yearly sightings in all continental U.S. states and irregular sightings in Hawaii. This species’ range also includes most of western Canada, all of Mexico and Central America and some sightings in northern South America – truly a widespread species. Being so widespread often leads some to dismiss this species. Hopefully this article will provide some reasons to observe some of the American Coot’s behaviors more closely the next time you are in the field.
The American Coot is in the Rail family (Rallidae), which includes other local species like Sora and Virginia Rails. These two species are much more secretive than the American Coot and far less abundant. Coots are medium sized, plump, aquatic birds measuring an average of 15 inches in length and weighing an average of 25.6 ounces with males being slightly larger than females. They have black heads and necks and slate-gray bodies with white, lateral undertail coverts. Most notably, Coots have white bills and white frontal shields. There is often a reddish-brown spot near the top of the shield. Their toes are not webbed like a duck but possess lobes that aid them with swimming and diving and that conveniently fold back with each step when traversing on land.
American Coots are extremely vocal, and their calls are usually the first thing you hear when birding near their habitats. Ornithologists recognize six different vocalizations in adult Coots. These vocalizations include recognition notes, courtship notes, alarm notes, perturbation notes, warning notes and intimidation notes. The reader is encouraged to listen to Coot vocalizations at Cornell’s Birds of North America site (https://birdsna.org). This wide array of vocalizations is believed to have developed because Coots spend much of their time in dense, emergent vegetation where visibility is poor. Interestingly, due to differences in the male and female syrinx (voice box), males can be distinguished from females with the female voice being typically low and nasal and the male voice high and clear. Along with calls, Coots will also splash about rather noisily to let their presence be known.
A wide variety of freshwater wetlands are inhabited by American Coots depending on the season. During breeding season, preferred wetland habitats need two characteristics; the presence of dense stands of emergent aquatic vegetation (preferably cattail or bulrush) along parts of the shoreline and deeper water within the stands during nesting and chick rearing. Many different types of wetlands including brackish waters and large lakes are utilized during migration. Winter habitats include all of the above along with estuaries, bays and lagoons.
American Coots are primarily herbivorous consuming a wide variety of aquatic vascular plants and algae. They will also eat some grasses and grains. Animals make up a small part of their diet, more so when they are feeding their chicks. Food is gathered while in the water by dabbling or diving. Typically food items are brought to the surface before being consumed with the exception of mollusks or aquatic insect larvae. It is not unusual to find Coots grazing on lawns and golf courses.
While there is some dispute, it appears that most pair bonding and courtship occurs on breeding grounds. American Coots are classified as socially monogamous, and pair bonding is somewhat different between new mates and those that have reunited after a separation. Birds bond and court at their initial meeting by touching bills (billing); followed by bowing of the submissive partner and the presentation of the neck and head; and finally by nibbling where the dominant partner buries its bill in the submissive partner’s feathers working its way along the length of the partner’s neck, back and breast. Already paired birds respond by bracing at their reunion. Bracing involves swimming rapidly towards each other with the front of their bodies elevated and necks erect. Establishing a territory is the next hurdle once the bond has been formed. Once breeding territories are established, they are defended aggressively, not only among conspecifics (other Coots) but also other species.
American Coots will construct up to nine nests in the course of laying two clutches of eggs and seven nests for a single clutch, with the number of clutches being dependent on latitude. Display nests constructed of coarse materials are built first. One display nest, presumably selected by the female, is further refined to become the egg nest. The egg nest is about a foot in diameter with a one-inch center cup of finer material to hold the eggs. Egg nests float on the water and are attached to emergent vegetation. They require constant attention to keep the waterlogged material from sinking and will typically disintegrate in 48 hours after being abandoned. A ramp is built to facilitate ingress and egress from the nest. The remaining display nests are left to disintegrate or become roosting platforms.
A range of 8-12 eggs is laid at the rate of one egg about every 24 hours. Described as subellipitical or conical to biconical, there is a greater degree of variation in shape between other Coot’s eggs than within a single clutch. There is also less variation between the background buff to pinkish color, speckling pattern and speck color within a clutch than between different clutches. These differences allow the parents to distinguish between their eggs and those of conspecific brood parasites or brood parasites of other species. Brood parasites lay eggs in the nest after the initial egg has been laid. Eggs hatch pretty much sequentially about 23 days after being laid meaning the first chick to hatch is the mother’s. The mother Coot imprints on the markings of the first young to hatch. Subsequent hatchlings typically follow the same pattern. Chicks that don’t match are drowned or pecked to death. The chicks are precocial and capable of leaving the nest after a short drying period. Coot chicks are covered in a thick black down with long, orange, stiff hair-like down feathers called down ornamentation. Down ornamentation along with brilliant head coloration consisting of a nearly bald scarlet crown, orange bill and blood-red shield stimulate the parents to feed begging chicks. Chicks lose all down ornamentation within four days. Once a few chicks hatch, the mother takes them to a newly constructed nest called a brood nest leaving the male to brood and defend the egg nest. Due to the sequential nature of hatching times, the egg nest is often abandoned before all of the eggs hatch. The chicks are closely guarded and fed by the parents. Between 30 and 60 days, the chicks become more independent and at 75 days can fly. They are driven from the parent’s territory after 80 days.
Historically, numbers of American Coots have decreased in the east, but they have extended their breeding populations in the west and are considered a species of least concern. Certainly they are dependent on healthy wetlands, and efforts to continue to preserve and renew our wetlands are necessary for their wellbeing.
We are fortunate to have abundant opportunities to observe and listen to this interesting species. Try to distinguish the male and female vocalizations the next time you hear the “All” American Coot.