by Cory Davis
Who doesn’t love to see that bright white head popping up on a mountain lake on a gray day? “There’s a bufflehead!” Always one of the easiest ducks to identify, even the females are distinctive with a conspicuous, white cheek patch.
Appropriately for Montana, their name refers to the large buffalo-like shaped head. Similarly, the genus Bucephala, which they share with their close relatives the goldeneyes, means bull-headed or large-headed. However, even with their large heads, they are one of the smallest North American ducks. Only green-winged teal are as small. It has also been called “spirit duck”, perhaps after emerging from the depths on a misty morning. Finally, the name “butterball” was used early on, though I’m not sure why such a small duck would warrant such a name. Perhaps it has an especially thick layer of fat to keep it warm in cold mountain lakes.
Male Buffleheads have a clean, white body and black back, and, on a sunny day, stunning green and purple iridescence on the forehead and neck. Only Hooded Mergansers have a similar large white head patch, but their dark bodies and thin black bills make them easy to distinguish. Female Buffleheads are mostly dull gray. In flight, note the male’s small size, black-and-white wings, fast wingbeats, and their tendency to wobble side-to-side.
Almost exclusively a North American duck, Buffleheads breed primarily north of the 48th parallel, with some exceptions. Western Montana is one of the few parts of the lower 48 where they can be found year-round. Good local spots to view one include the Creston Wetland (year-round), many of the lakes in Glacier National Park during the breeding season (June-August), and the north end of Flathead Lake or West Valley ponds during the spring and fall migration. Many birds winter in sheltered coves or wetlands on the coasts, though they can also be found on lakes in most states and south to Mexico in the cold season. They don’t usually flock in large numbers like many wintering waterfowl.
Unlike most duck species, Buffleheads are monogamous and will mate with the same partner for multiple years. During courtship, males use head-bobbing and quick swims to attract the attention of females. Like skidding to a stop on your skis and spraying snow on your ski partner, males also employ abrupt water landings to impress a female. Males will compete quite aggressively for the females and to defend their territories.
Buffleheads breed in conifer and riparian forests near lakes and ponds, and are common breeders in Montana’s lakes. They are very reliant on Northern Flickers for their nest cavities, usually placed in aspen or poplar trees. Their small size allows them to fit through Flicker holes, unlike other larger cavity-nesting ducks. They will occasionally use a Pileated Woodpecker cavity, if it’s not already occupied by someone else. They will also use nest boxes that have an appropriate entrance size (2.5-inch diameter) and are placed in a forested area near a small pond or lake. Clutch size is usually 9-12 eggs, and the juveniles have brownish-gray down similar in color to the mother.
Patience is needed when pointing this species out to a fellow birder, as Buffleheads are very active diving ducks. They spend half their feeding time above water and half below. One early European hunter recounted watching the duck dive and grab a root to remain submerged for five minutes to allow danger to pass!
In lakes and ponds, Buffleheads forage for aquatic insects, crustaceans, and mollusks. They prefer open, shallow water for foraging with little submerged vegetation; however, they will feed on seeds of aquatic vegetation during migration. On the coast, they dine on fine seafood including shrimp, crab, mussels, and small fish.
Bufflehead populations are stable and have actually increased across their range in recent decades. Buffleheads are taken during the hunting season, but they are usually not a prime target, probably because of their diminutive size. Clearing of boreal forests in western Canada for lumber may be reducing available nesting sites, but this is one of their few current threats. Good news for a beautiful and truly Montanan duck!