Buffleheads

     Saturday was the last day of winter. It seems fitting that there were winter ducks in the East River -- some red-breasted mergansers and a pair of bufflehead ducks. The buffleheads were far from shore but their distinctive patterns make them easy to recognize from a distance.

The male bufflehead has a white body, black back, and a large dark iridescent head with a triangular patch behind each eye. (The bufflehead's genus, Bucephala, is from words that mean ox and head, referring to the big-headed look.)

The female bufflehead is mostly dark above, mostly grayish underneath, and lighter on the breast. A large oval white patch on the side of the face and a little patch of white near the back of the wings are usually visible from a distance. 

  
     When male and females of a species look different like this, they are called sexually dimorphic (di=two, morph=shape). Male and female buffleheads are about a foot long and both have small gray bills.

     Buffleheads, Bucephela albeola,  spend the winter throughout the United States. They migrate north to breed. The pair pictured here will probably find a nice lake in Canada and raise a family there. Somewhat unexpectedly, they make their nests in trees. And, even stranger, they almost always make them in holes excavated by woodpeckers in previous nesting seasons.

     Don't be surprised if a bufflehead you are watching disappears before your eyes. Buffleheads dive under water to find aquatic plants and insects, fish eggs, mollusks, and crustaceans. Whereas mallards and many other familiar ducks stay on the surface and tip over with their heads under water and their feet n the air, buffleheads go completely under the surface and can come up surprisingly far away.

One minute the bufflehead is rearing up and flapping his wings....

And the next minute there is nothing but a disappearing tail and a splash...