Northern Harrier (Circus cyaneus) also known as hen harrier, marsh hawk. Chances are good that you have encountered a Northern Harrier if you have spent even a short amount of time in the sagebrush shrub-steppe, or have driven by large patches of habitat. These majestic, medium-sized hawks are found gliding low and slow over marshland or grassland. Males and females possess a distinctive white rump patch that is most obvious in flight and can be seen from far away. They are a year-round resident of eastern Washington, and in winter are sometimes discovered roosting in groups on the ground with Short-eared Owls, another permanent resident. During the breeding season, in an attempt to win female affection, males will perform a sky dance, which consists of elaborate flying barrel rolls over dry upland habitats
Unlike other accipiters who rely heavily on vision, these owl-resembling hawks use both sight and sound to hunt for prey. Their diet consists of small mammals, small birds, reptiles, and amphibians, but the Northern Harrier can also catch and subdue larger targets, like rabbits and ducks, by drowning them. Their disk-shaped face is made up of stiff feathers to direct sound to their ears. This design reveals their prey through sound as they weave over fields. The male Northern Harrier needs to be an especially sharp hunter because they can have as many as five mates at once, although typically have one or two mates when food is not abundant. This solo male is the main provider; supplying most of the food for his offspring and his mates, while the females incubate the eggs and brood the chicks.
Conserving large, continuous areas of native vegetation, including wetland and riparian zones, is critical to the Northern Harrier because they nest on the ground in dense vegetation, such as willows, grasses, sedges, reeds, bulrushes, and cattails. Without habitat, the Northern Harrier would not be able to successfully reproduce and help to keep small mammal populations in check, such as mice, voles, rats and shrews. Norther Harrier nests are susceptible to predation from coyotes, dogs, skunks, raccoons, foxes, American Crows, Common Ravens, Great Horned Owls, and even deer and livestock, which may trample eggs and nestlings underfoot. Northern Harriers are common, but their populations are steadily declining 1% each year since 1966 due to habitat loss, drained wetlands, development, and reforested old farmland. Adult and juvenile Northern Harriers are vulnerable to a fatal consequence if they eat poisoned animals or small mammals that possess pesticide buildup in their system. Like the Bald Eagle, the Northern Harrier population declined in the mid-twentieth century due to DDT; populations have since rebounded after DDT restrictions went into effect in the 1970’s. In conjunction to loss of habitat pressures, Northern Harriers also face a scarcer food supply. The population of small mammals that Northern Harriers prey upon have been reduced due to overgrazing, pesticides, and reduced shrub cover from crop field expansions.
How can you help? Douglas County can do our part to conserve these regal raptors by providing healthy, continuous sagebrush shrub-steppe and wetland habitat. Foster Creek CD has opportunities and funding to assess and improve rangeland, cropland, and wetland or riparian habitat. If you are interested in learning more about conservation stewardship or enhancing degraded habitat, contact us today, (509) 888 – 6372!
Literature Credit: “Northern Harrier.” The Cornell Lab of Ornithology: All About Birds. Cornell University, 2015. Web. 27 March 2017.
Images Credit: “Northern Harrier (Circus cyaneus).” Hawk Mountain. Hawk Mountain Sanctuary, 2017. Web. 27 March 2017.
“Conservation & Monitoring.” RSPB: giving nature a home. The Royal Society for the Protection of Birds (RSPB), 2014. Web. 27 March 2017.