Tom Pappadakis, age 11, of Las Vegas, Nev., for his question:

HOW LARGE IS THE CANVASBACK DUCK?

The canvasback is a large duck of North America that dives under water to get the plants it eats from the bottom of ponds and lakes. The duck measures from 20 to 24 inches long and weighs between two and three pounds.

The duck receives its name from the canvas colored body of the male bird. The male has a reddish brown head and a black collar around his breast. The female is gray and brown.

The canvasback duck makes its home from Nevada east to Nebraska and north as far as Alaska. In the winter it flies to the Atlantic and Pacific coasts of the United States.

Canvasbacks usually build their nests in clumps of weeds and grass in marshes. They line the nests with gray down. The birds lay seven or more greenish or olive gray eggs.

Canvasbacks cannot fly while they are growing new feathers after the nesting season. At other times they can fly high and fast, often traveling in V shaped lines.

Canvasbacks have a fine flavor and hunters prize them.