During the winter, the Sweetwater Wetlands on Tucson's west side are home for numerous Northern Shoveler (Anas clypeata) ducks.

Not only are the waters covered with them, sleeping and resting Northern Shovelers also crowd the edges of the interior islands in the wetlands.

Northern Shovelers have long, shovel-shaped bills edged with comb-like projections that they use to sieve the water for food.

These ducks are monogamous, and the dissimilar males and females are often found together.

Female Northern Shovelers are mottled brown, but they can be distinguished from other similar female ducks by their unusually large bills. Male Northern Shovelers have an iridescent green head, white breast, and rust-colored sides.