Northern Harrier2005

Northern Harrier2005

Summary:

Worldwide Species Action Plans

Northern Harrier action planThe northern harrier (Circus cyaneus) is considered globally secure by the Natural Heritage Program because of its wide distribution across North America. However, because of its low density and often nomadic behavior, assessing this species population status and evaluating trend data are difficult, even with large-scale and long-term monitoring programs such as the Breeding Bird Survey. Nevertheless, historic and recent evidence suggest that the number of breeding harriers has declined across the species range. USDA Forest Service Region 2 represents a segment of the core of this species breeding range, and Breeding Bird Survey data suggest that northern harrier populations in Region 2 states have exhibited long-term declines that substantially exceed national trends. Breeding northern harriers require large tracts (greater than 100 ha) of habitat. The greatest threats to northern harriers in Region 2 are loss of wetland and grassland habitats, and the effects of habitat fragmentation, primarily from agricultural production. Northern harriers nest and hunt in moderate to tall vegetation with dense litter cover. Agricultural activities that remove vegetation, such as grazing and mowing, can make habitat unsuitable or lower habitat quality, as well as destroy active nests. Habitat fragmentation also may reduce recruitment by causing higher nest predation rates and increased competition with other predators for their primary prey items.


  1. Circus cyaneus hudsonius
  2. North and Central America
  3. Circus cyaneus cyaneus
  4. Europe, c and n Asia
  5. Circus cyaneus
  6. NA, EU widespread


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