is a specific kind of: bird genus.

has as a member: Anas platyrhynchos, mallard | Anas rubripes, black duck | teal | Anas penelope, widgeon, wigeon | Anas clypeata, broadbill, shoveler, shoveller | Anas acuta, pin-tailed duck, pintail.

is a member of: Anatidae, family Anatidae.