From Opus

Genus: Circus

[edit] Description

About 13 species of Harrier found worldwide (except for Antarctica). They are medium-sized raptors, females being larger than males. Harriers have long wings, tails and legs. They forage for prey by quartering low over wetlands, grasslands and shrublands. Like owls, they have a feathered cowl around the face; this is thought to help with auditory detection of prey.

[edit] Taxonomy

Circus is a genus in the family Accipitridae.