This harrier has a white rump and long wings. It searches for prey over South American marshes and grasslands; a breeding-season study in southern Chile recorded males passing prey to females in the air.
It has a white rump, long wings and tail, black wingtips, and fine cinnamon barring below. Males are smaller and gray; females are larger with a brown back.
It flies low and slowly over grassland and marshes while searching for prey. A breeding-season study at Torres del Paine in southern Chile observed males transfer prey to females in midair.
An extinction-risk assessment has not been added yet.