The Northern Harrier (Circus cyaneus) is of major conservation and management concern in the northeastern United States. We studied habitat use of foraging adult male and female harriers on Nantucket Island, Massachusetts among four habitat types: grassland, shrubland, mowed, and burned. Overall, foraging indices were not correlated to nest proximity and harriers foraged significantly less frequently in mowed habitat than in the other habitat types. Management of harrier habitat in the northeastern United States may not exclusively require grasslands, and mowing reduces foraging habitat.