In winter months the distribution shifts southward occupying an area from it the southern states of the U.S. to Central America, where the largest winter concentrations occur. The Northern Harrier has several characteristics which distinguish it from other birds. They have specialized feathers around their face in the shape of a disk, which focuses sound into their ears. Adult harriers have yellow eyes.
Adult males are gray on their dorsal side.
Ventrally they are white except for spots on their chest and black wingtips. Adult females are a brown color all over their body, except for underneath their wings where there are white stripes. Immature males and females resemble the adult female but they have a darker shade of brown covering the dorsal side, and a brownish rusty color underneath. Immature harriers have brown eyes. Other food sources include insects, small rodents, and small reptiles.