The ducks at Agua Caliente Park here in Tucson have become very tame because people often feed them. The larger, more aggressive Mallards (Anas platyrhynchos) get most of the food, but some of the smaller species of duck like these wintering male American Wigeons (Anas americana) are quick to dart in and snatch what food they can.
Male Mallards have an iridescent green head, white neck ring, and rust-colored chest. Male American Wigeons in breeding plumage have a mask of iridescent green with a broad, white crown stripe, while those in non-breeding (eclipse) plumage are a mottled brown like the females. These are mostly in breeding plumage. Both male and female American Wigeons in any plumage have light bluish-gray, black-tipped bills.