Northern Harriers—also called “marsh hawks”—favor wet meadows but also occupy grasslands, croplands, sedge meadows, marshlands, sloughs and prairies. An important requirement of their habitat is an abundant population of voles—also called meadow mice. However, Harriers also will eat other small mammals, amphibians, reptiles and some invertebrates.
The Northern Harrier sometimes hunts small sparrows and songbirds, but these prey will fight back. You might see a Harrier being mobbed by a flock of small birds; the Harrier usually will try to escape these mobs by darting quickly back and forth.