|A Bufflehead drake
Among our smallest ducks, Buffleheads (Bucephala albeola) are one of the most noticeable winter ducks along rivers and large waterways. Their common name is a corruption of "buffalo" and "head" due to the oversize appearance of their heads, particularly in the drakes (males). Their Genus Bucephala is also Greek for "broad forehead" or "bull-headed." The rest of their scientific name albeola is Latin for "little white" and refers to the overall look of the small adult drakes as well. Linnaeus originally named them Anas albeola in 1758.
This diminutive waterfowl, the smallest diving duck we have, with the Green-winged Teal being its only challenger to smallest duck in all North America, averages 14 inches and rarely gets to over a pound and a half. It has numerous other common names including Black-and White Duck, Bumblebee Duck, Butterbowl, and Butterball. The latter two names can refer to its chubby shape, or to the amount of butter that needs to be added to make these game birds palatable. They are also sometimes called "Pound of Butter" due to their shape, average weight, and again the amount of butter needed to make them them edible.
Though these tiny ducks have a chubby, big headed look to them, the adult males (drakes) are also quite striking. From a distance they have strongly contrasting black and white appearance. In reality, when seen closeup, their head colors have a glossy greenish and purplish gleam to them. It makes them quite distinctive even from a distance. The females and first year males are a darker overall color with a distinctive white cheek patch behind the eye, which along with size differentiates them from their larger cousins in the same Genus, the Goldeneyes.
|A Bufflehead drake follows a hen along the water.
Buffleheads are diving ducks, with their feet set well back on their bodies to assist in swimming. They are awkward on land, and are rarely seen walking other than when the females are leading the young to the water. They prefer diving in shallow (less then 15 feet deep usually) water. They spend quite a bit of time underwater, easily submerging themselves every few seconds for 10-25 second dives. Their quick disappearing and appearing acts have given them another common name: Spirit Ducks. Here's a short video of several hens diving:
The diet of Butterballs is about 80% animal matter. The food preferences change seasonally. About 40% of their summer diet consists of insects such as dragonfly and damselfly nymphs. This changes to crustaceans, mollusks and occasional fish in the winter, particularly since many spend winters in open shallow saltwater bays and estuaries where insects are scarce.
Like most diving ducks, Buffleheads have to run or patter along the surface prior to being able to get airborne. But these little divers don't need near as much of a take-off strip as most other diving ducks. They seem to almost effortlessly take off after just a few steps along the water surface. Some stories even tell of them coming straight out of an underwater dive and taking off, though I myself have never witnessed this.
|A Butterball hen patters across the surface of the water before taking flight.
Butterballs live throughout northern North America and are strong fliers. Some have ended up in Japan and other parts of Asia, while others have been seen in the British Isles and other parts of Europe. Though they tend to fly low over the water, they can also fly at very high altitudes when migrating and have a swift and direct flight pattern.
|A Butterball drake flying in its typical low pattern over the water.
Unlike many other birds, Buffleheads are fairly monogamous and will remain with the same mate for several years at a time. They rarely will try and breed until their second year of age. They usually pair up in late winter or very early spring. The drake typically does a head bobbing display and tries to get the hen to follow him. Males tend to display aggressively against each other and quarrel quite a bit. Here's a short clip of them displaying:
Buffleheads migrate back late in the season, they're one of the last ducks to leave for their breeding grounds, waiting until the ice breaks in their northern territories. They normally are restricted to nesting in Canada and Alaska, though a few stray into the USA and long mountain chains. They show great nest fidelity, returning to use the same nest sites year after year while they're available.
Interestingly, they have a similar range distribution as a type of woodpecker called the Northern Flicker. This is because they've evolved to make use of the holes flickers make to nest in. They've evolved their small size so they can fit into these cavities (mostly in aspen trees near water) which most other larger cavity nesting ducks cannot use. It is uncommon for them to use any other woodpecker holes or larger holes because they end up being out competed, including by their Goldeneye cousins. They will however use man made nesting boxes that have similar proportions in hole size.
Hens lay 4-17 creamy white eggs (though 8-10 is more typical) in their nesting hole which they line with feather down pulled from their chests. Approximate 30 days later, the chicks all hatch at pretty much the same time. A day later, they jump from their nest cavity (which could be 40 feet up though, 8-10 is more typical) to their waiting mother below who leads them to the water. Less than 2 months later, the young fledge. Occasionally, chicks separated from their siblings may join another mother's brood. If they survive their first few months, they can live quite a long life. The oldest on record was one that was banded and released that was 18 years and 8 months old in 1975.
Butterballs, despite decoying easily, are not heavily hunted. Because of their high animal diet, they are thought to taste fishy and unpalatable (even if covered in butter) and so not sought after. Their numbers, despite loss of habitat, have remained steady over several years and they population is considered stable.
|A Bufflehead hen.
|A small flock of Buffleheads feeding on a river.