Waterfowl is a term that refers to ducks, geese and swans. Throughout North America, the most common waterfowl in cities and suburbs are Mallard Ducks and Canada Geese. Both species are highly adaptable, and often gather in large numbers in city parks and on freshwater beaches.
Although Mallards and Canada Geese are migratory, large flocks remain throughout the year in the mild Pacific Northwest climate, where they can find food and shelter year-round.
In breeding plumage, male Mallards are distinguished by their green heads, white neckband, chestnut breast, and black, upcurled tail. Females are mottled brown overall.
Mallards are dabblers, feeding mostly at or just below the surface of the water. They eat seeds, sedges, pondweed, aquatic insects, fish eggs, and mollusks. On land, they eat grass and weed seeds.
Mallards build their down-lined nests of leaves and grasses at the edges of sloughs, lakes or marshes. Females incubate 8 to 10 eggs, which hatch in about 26 days. Shortly after hatching, the ducklings' mother leads them to water. They first fly about two months after hatching. Mallards are genetically capable of cross-breeding with other species of ducks and often produce hybrids.
There are at least 11 different subspecies of Canada Geese in different North American ranges. Males and females are alike in color, but the male is somewhat larger. Like dabbling ducks, geese feed at or just below the water ‘s surface, eating tubers, roots, leaves and eelgrass.
On land they graze for grasses, bulrushes, clover and other plants. In the fall, they pick up waste grain and corn from stubble fields in agricultural areas.
Geese form lifelong pair bonds, but if one mate dies, the survivor will find a new mate. Geese nest on the ground and on platforms near water. With the male standing guard nearby, the female incubates 5 to 6 eggs for about one month. Goslings follow their parents into water within a day of hatching, and they fly from 63 to 86 days later.
Mallards and Canada Geese are frequently blamed for trampling lawns and for polluting water and grass with accumulated feces. They find abundant sources of food and shelter in parks and along lakes and ponds. They frequently stay in one place for long periods of time. Habitat modification can encourage waterfowl to disperse.
Supplemental feeding attracts large flocks of waterfowl and promotes their dependence on handouts which do not provide proper nutrition for the birds. When left to feed on their own, waterfowl consume and help control aquatic plants such as millfoil and algae.
But when people dump their uneaten food and leftovers such as bread and chips, the rotting food can compromise water quality and promote bacterial infections in animals.
Above: A Canada Goose