page_title: Swainson's hawk
section_title: Status and conservation
hierarchical_section_title: Swainson's hawk / Ecology / Status and conservation
caption_attribution_description: English: Photo of Snake River Birds of Prey National Conservation Area
context_page_description: Swainson's hawk, is a large Buteo hawk in the Accipitriformes order. This species was named after William Swainson, a British naturalist. It is colloquially known as the grasshopper hawk or locust hawk, as it is very fond of Acrididae and will voraciously eat these insects whenever they are available.
  Their breeding habitat is prairie and dry grasslands in western North America. They build a stick nest in a tree or shrub or on a cliff edge. This species is a long-distance migrant, wintering in Argentina; it has been recorded as a vagrant in neighboring Chile, in the island countries of the Dominican Republic, and Trinidad and Tobago, and in Norway.
  This species or its immediate predecessor is the ancestor of the Galápagos hawk, as demonstrated by recent research. Then later diverged from the mainland birds perhaps 300,000 years ago, a very short time in evolution.
context_section_description: Swainson's hawk has suffered population declines since the first half of the twentieth century and was Blue-listed in the United States from 1972 to 1982. It has since been placed on the National Audubon's List of Special Concern in 1986. It is now listed by the United States Fish and Wildlife Service as a Category 3C candidate. Swainson's hawk was removed from the active federal list because it was found to be more abundant than previously thought; it is not considered a threatened species by the IUCN. It remains listed as a threatened species by the California Department of Fish and Game as it has been since 1983.
  A major cause of Swainson's hawk population decline was pesticide use in its wintering grounds of Argentina. Farmers there were using pesticides (DDT and monocrotophos) to control grasshopper and locust infestations, and Swainson's hawks were ingesting these pesticides in several different ways, but mainly by gorging themselves on the insects as they lay dying. The U.S. has worked with Argentine farmers to resolve this problem.
  Swainson's hawk has adapted well to grazing and pastureland and seems to be holding its own over much of its breeding range, from northern Mexico to the southern parts of the prairie provinces. However, far western populations, like that of Oregon, and southern California, have drastically declined, often due to habitat loss or incompatible agricultural practices. A possible reason for declines in parts of its range may be agriculturally motivated reductions in populations of both ground squirrels and grasshoppers, major seasonal foods.
  Although often nesting close to human activity, some Swainson's hawks are very easily disturbed at the nest and often desert, especially early in the season. The bird is often quite tame and an easy target for shooters traveling isolated prairie roads. The species may also be affected in ways yet to be understood by some insecticides and herbicides, including those used on its wintering grounds.
caption: Snake River Birds of Prey National Conservation Area
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