October Nature Almanac: Irascible Mud Hens
by Scott Severs, Ruth Carol Cushman, and Steve Jones
October 2021
They've been here all summer, and they'll probably be here all fall and winter too—those noisy little dark, duck-like birds that like to dabble around in the wetlands of eastern Colorado. These American Coots are a delight to watch in September and October when they are joined by ducks and geese migrating from the waterfowl production areas of the northern Great Plains to join flocks of coots foraging on the abundance of aquatic plants that have grown over the summer.
Adult American Coot.
Coots belong to the rail family, which includes cranes and the sora. Many species in the rail family, especially the coots and gallinules, remind us of chickens adapted for an aquatic lifestyle. Instead of webbed feet, coots have lobed feet to aid them in swimming and diving for their favorite greens, as well as the occasional fish or tadpole. Coots move around like the best all-terrain vehicles, often leaving the water to forage on grasses and weeds along the shorelines of ponds and lakes. This can at times leave them a bit muddy, alas the nickname “mud hen.”
Distinguishing coots from ducks is fairly easy. The best field mark in adults is their sharp, short triangular bill, which is white in color, and the reddish "shield" on the forehead. Overall, coots are a dark slate black with white feathering along the sides of the tail. As swimmers, they are not nearly as smooth as ducks—their heads often bob up and down, pigeon-like. Because their stubby wings do not generate much lifting power, coots—like diving ducks and loons—must run along the water surface during takeoff in order to fly.
American Coots provide hours of interesting behavior-watching, easily observed by any amateur ornithologist. During courtship a male will paddle low in the water while displaying his striking white outer tail feathers and raising his wings over his head. Chases and fights usually stem from territorial defense, and can be dramatic. Birds in conflict will rear up in the water and strike at each other with their sharp claws and bills. We’ve watched many of these dramas while sitting on the bench on the boardwalk at Walden Ponds.
Broods of coot chicks have been thoroughly vetted by the parents for genetics and survivability. First, females can distinguish their own eggs and usually will not incubate any eggs laid by other females in their nests. If they happen to hatch an unrelated chick, which they determine by hatching order, they’ll ignore or peck it to death, a difficult behavior for us humans to comprehend. Finally, they fine tune their broods to available resources, only feeding the healthiest chicks at first, and then feeding weaker brood members if food resources are available, thus ensuring that only the fittest chicks survive.
One unique interaction to watch for during autumn occurs between the coot and the American Wigeon, a type of dabbling duck similar in habits to a Mallard. The coot swims under water, grabs large masses of aquatic vegetation, and brings it to the surface to consume, at which time a wigeon (which cannot dive nearly as well) steals some of the food from the coot. Coots do not seem to mind this too much, possibly because they benefit from the watchful eyes of the wigeons while they're foraging down below. In return for their guard duty, the wigeons get free food!
Despite their abundance, coots deserve our attention. Their battles, courtship behavior, and interactions with other waterfowl are easily observed and allow us a glimpse into the behaviors of birds. In Boulder County, look for good numbers of coots at Walden/Sawhill Ponds, Boulder Reservoir, and Sombrero Marsh.