This is one of the migratory duck species that can be spotted on Boomer Lake throughout the winter (if you know what you’re looking for). These are small ducks (technically they’re the smallest diving duck in North America), which frequently dive for their food and then pop up within thirty seconds somewhere close by.

The males are fairly distinctive birds—they have a large white patch that wraps around the back of the head, and can be seen in the company of their mate (they’re also one of the few duck species that is monogamous for several years).

These are birds where there is a distinction between the sexes.

Adult males have a large white patch that wraps around the back of their otherwise dark head. Adult males also have a white breast, and black back with an large white patch on the upper wing (seen in flight).

Females (and immature males) have an oval, white cheek patch. The females (and immature male) have more of a gray-brown coloring, and a smaller white patch on their wings (again seen in flight).

The bufflehead can be spotted within North America at some point during the year. They breed mainly in Alaska and parts of Canada, and winter in the lower forty-eight states (though some states may only see them during the migratory periods).

They breed near ponds and lakes in the boreal forests and aspen parklands of Canada and Alaska.

While they will mainly stick close to the coasts during the winter (and can be spotted within sheltered coves, harbors, estuaries, or beaches—they avoid open coastlines), they can also be spotted within the inner part of the US as well.

Oklahoma is within their winter range, so the best place to look for them is out on the waters.

There are always a small number of buffleheads out on Boomer Lake during the winter months, though they head north fairly early during spring migration.

In terms of diet, buffleheads go for the aquatic invertebrates, crustaceans, and mollusks. These ducks aren’t dabblers (with the exceptions of the ducklings); they will dive for their meals, with an average dive time of twelve seconds.

On freshwater lakes and ponds, they will feast on damselfly, dragonfly, and midge larvae, water boatmen, mayfly larvae, caddis-fly larvae, amphipods (large zooplankton), and snails during the winter.

They will also eat seeds and other plant matter during the fall and winter.

Along the coasts, they will eat shrimp, crabs, amphipods, isopods, snails, mussels, herring eggs, sculpins, and ratfishes.

Their breeding range is limited by the distribution of Northern Flickers. Why, you may ask? Because they use abandoned northern flicker nests as their own, since they’re the smallest diving duck in North America—they can fit into the nesting cavities dug by northern flickers, that other larger ducks can’t fit into.

These are also one of the few duck species in which mates will actual keep the same mate for multiple years.

Fossils of buffleheads have been found in Alaska, California, Florida, Illinois, Kansas, Texas and Washington. They usually date from the late Pleistocene period (approximately 500,000 years ago), though one fossil found in California dated to the late Pliocene period (which was about two million years ago).

Reference: https://www.allaboutbirds.org/guide/bufflehead