The patch of yellow at the base of the bill is a helpful field mark to identity the Tundra Swan. Tundra Swans nest in the arctic and stop at the Horicon Marsh during migration. They are North America’s most numerous swan species. Trumpeter Swans, on the other hand, nest at the Horicon Marsh during the summer. They lack the yellow patch at the base of the bill.
The slope of the head helps to distinguish the Canvasback from the commonly found Redhead. Male Canvasbacks have red eyes and black beaks. Male Redheads have a rounded head, yellow eyes, and a gray beak with a black tip. According to the Cornell Lab of Ornithology, “The species name of the Canvasback, Aythya valisineria, comes from Vallisneria americana, or wild celery, whose winter buds and rhizomes are its preferred food during the nonbreeding period.”
The Green-winged Teal is not likely to be confused with another species of duck. They are one of the tiniest ducks. The striking green and chestnut color on the head and neck of the male sets it apart. They are typically found at the Horicon Marsh during the summer and during migration.
There were Hooded Mergansers, Northern Pintails, Northern Shovelers, Ruddy Ducks, and a host of other waterfowl swimming in the water along Highway 49 today. It is a great time to visit the Horicon Marsh and see the variety of species migrating.