Known for years as the Marsh Hawk, the Northern Harrier was labeled as it is currently in the 1970's. The Northern Harrier is perhaps the only North American diurnal raptor with a distinct facial disk.
Adult males are 17 to 20 inches long and have wingspans of 40 to 45 inches. Adult females are 19 to 24 inches long and have wingspans of 43 to 54 inches. The males are light gray on the top sides, with darker grey barring on the tail and black wing tips. The undersides are white barred sparsely with brown. Females are mostly brown; pure brown above and off-white streaked heavily with brown below. The tail is light brown barred with darker brown, and has a white tip. Both sexes have a white patch on the rump just above the tail. Immatures resemble the females. See Notes- Reverse Sexual Dimorphism
The Harrier is found almost throughout North America. Found from the Arctic tundra boundary in the north to Panama; they avoid the tropics of the Yucatan Peninsula. They also live throughout Cuba. Not found along the coast of Alaska or the Aleutian islands. The Harrier prefers grassland and open areas; it seems to prefer marshes and wet grassland over dry prairie.
Nests are built on the ground out of sticks and grass, usually in wetland areas. 3-9 eggs are laid, although 5 seems to be the norm. Usually whitish unblemished by brown, but may be marked sparsely with brown. The eggs are incubated by the female for 31-38 days. The male provides food for the female harrier and nestlings. The young make their first flight in 5-6 weeks. Harriers are not mates for life, but for one season. Often during vole population increases, a male harrier will have more than one mate (polygyny). See Notes- Breeding Groups
The Harrier is mostly dines on small rodents, although it will take insects, reptiles and amphibians. Often the harriers are dependent on rodent populations, such as the voles, and will follow them if they move to another location.