American Coot visit Cobourg Harbour

Nature Notes for March 27, 2015

“There are some strange looking birds at Cobourg Harbour in amongst the Mallards. I know that this isn’t a very good picture, but you could help me identify them?” This paraphrases a request I received via the Willow Beach Field Naturalists web site last week. Fortunately, the identification was not difficult, even from a blurry photo.

They were American Coots. Coots are water birds, in the family that includes rails, moorhens and gallinules.

And they are strange looking. They are gray, about the size of a small duck, but with a small head and white chicken-like beak. The adults have a white “shield” on their forehead. Sometimes when they are on land, their oversized feet are visible. The feet seem several sizes too big for the size of the bird. Instead of webbed feet like ducks, coots’ toes are lobed. There is a fleshy projection along the side of each toe. This is an adaptation for walking on mud and floating marsh vegetation. These big toes are essentially snowshoes for mud.

 American Coot. Note the huge feet! 

photo © Rob Lonsberry Photography

In mild winters, a few have spent the winter in Cobourg Harbour. If the weather was really nasty for a few days, they took refuge in the storm drain that feeds into the yacht basin. They would probably have had a really difficult time this past winter and the ones being seen now are probably migrants.

Coots are quite eclectic in their choices of food, eating vegetation, some seeds, insects and aquatic invertebrates. The proportion of each in their diet depends on the season. American Coots are often, as at Cobourg, in amongst flocks of ducks. This is not just because they are waterbirds. They will frequently try to steal food that the ducks bring to the surface. Although coots can and do dive, the ducks can dive deeper than the coots and therefore have access to food that the coots can’t reach.

American Coots are uncommon and local breeders throughout Ontario’s marshes. In Northumberland, they have become quite rare breeding birds. A few may still breed in the Presqu’ile marshes, but even there they are hard to find in the summer. In Northumberland, American Coot is much more common as a migrant than as a breeder.

For nesting, coots need about a 50/50 mix of open water and emergent vegetation (i.e. cattails, bulrushes). They build floating nest platforms out of marsh plants that are anchored firmly to upright stems. They also build floating platforms for roosting and for the use of their chicks. The chicks are fed by their parents for several days, but they are able to swim and dive almost as soon as they hatch.

American Coots are quite sensitive to changes in water levels, so they may occupy a marsh one year only to abandon it if the water level goes up or down.

When they are present, they are often detected by their loud calls. Because these vocalizations are very similar to Common Gallinule, they can’t be identified to species by voice alone.

Although they migrate far enough south to have open water throughout the winter, they are not strong flyers. They have to run along the surface of the water, flapping furiously, for quite a distance before they become airborne.

Although coots are frequently seen as migrants among the flocks of migrating ducks, as soon as the ice clears from marshes, they will disperse to breeding areas. These areas may be as far away as the northern prairies.