Ferruginous hawk (Buteo regalis)

A ferruginous hawk stands on the ground
Ferruginous hawk (Brett Billings - U.S. Fish and Wildlife Service)
Category: Birds
Ecosystems: Shrubsteppe
State status: Threatened
Vulnerability to climate change (More details)

Low-
Moderate

If you see this species, please share your observation using the WDFW wildlife reporting tool or email us at  wildlife.data@dfw.wa.gov. Be sure to include a photo of the species for verification and location (latitude/longitude coordinates) of your observation. 

The population size of ferruginous hawks in Washington is low. This species is impacted by the loss and fragmentation of shrubsteppe and grasslands from agriculture and residential development and associated declines in distribution and abundance of its primary prey, jackrabbits and ground squirrels. Direct sources of mortality include illegal shooting, electrocution from powerlines, and collision with wind turbines.

Description and Range

Physical description

The ferruginous hawk is a relatively large hawk with broad wings, a large head, robust chest, and feathered legs. This species averages 23 inches in length and has a wingspan of 56 inches. Females are noticeably larger. Males and females have similar plumage. This hawk can appear in two color phases. The light “morph” (phase) is snowy white below, reddish-brown above, grayish head, whitish tail, and underwing linings. The dark morph is a dark brown head, chest, and belly, and whitish tail and underwing linings. Underwing covert feathers are faintly speckled. Toes, "cere" (upper beak membrane), and beak margins are yellow. 

Ecology and life history

A ferruginous hawk flies low of sagebrush near a barbed wire fence with wooden posts
Ferruginous hawk flying low over sagebrush Wallace Keck - National Park Service

Ferruginous hawks are migratory and occur in arid grasslands and shrubsteppe habitats.

The diet of Washington ferruginous hawks consists primarily of small to medium-sized mammals, such as jackrabbits, pocket gophers, mice, and ground squirrels, but often includes birds, reptiles, and insects.

This species arrives on its breeding areas from late April through July. Nests occur on small rock outcrops on the slope of steep hillsides or canyons or in isolated trees, such as junipers. The hawks often build on the remains of pre-existing hawk or crow nests. Conservation managers often take advantage of this behavior, providing artificial nests for hawks to build upon to help boost populations.

Following nesting, ferruginous hawks typically migrate to the eastern front of the Rocky Mountains to exploit abundant ground squirrels, followed by a migration to central California.

Geographic range

Washington state is on the northwestern edge of the species' breeding range. Over 200 territories have been documented in Washington, with Franklin and Benton counties together hosting about 60 percent. Grant, Walla Walla, Adams, and Yakima counties have had 13 or more territories each.

In 2002, only 20 percent of historical ferruginous hawk nesting territories in Washington were occupied, with many vacant for years. The current population size is unknown, but likely is very small.

The map illustrates potential range and habitat distribution of this species in Washington. For a map of worldwide distribution and other species' information, check out NatureServe Explorer.

Map of Washington showing boundaries of the ferruginous hawk potential range based on its habitat distribution occurring in 14 eastside counties: Adams, Benton, Columbia, Douglas, Franklin, Garfield, Grant, Kittitas, Klickitat, Lincoln, Spokane, Walla Walla, Whitman, Yakima.
WDFW State Wildlife Action Plan

Climate vulnerability

Sensitivity to climate change

Low-
Moderate

Little to no information exists regarding ferruginous hawk physiological sensitivity to temperature and precipitation. Overall sensitivity of this species may be enhanced due to prey specialization (i.e., jackrabbits, cottontail rabbits, ground squirrels, prairie dogs, pocket gophers) and habitat requirements (i.e., grasslands). Warmer temperatures may benefit this species due to grassland expansion. Increased extreme weather events (e.g., heavy rain and high winds) may affect hawk reproduction and survival. Droughts that lead to declines in prey may adversely affect this species.

Confidence: Moderate

Exposure to climate change

Low-
Moderate

  • Drought
  • Increased storminess and winds
Confidence: Low

Conservation

This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
This species is identified as a Priority Species under WDFW's Priority Habitat and Species Program. Priority species require protective measures for their survival due to their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal importance. The PHS program is the agency's main means of sharing fish and wildlife information with local governments, landowners, and others who use it to protect priority habitats for land use planning.

Conservation Threats and Actions Needed

  • Agriculture and aquaculture side effects
    • Threat: Loss, degradation, and fragmentation of shrupsteppe foraging habitat and associated declines in distribution and abundance of major prey species, especially jackrabbits and ground squirrels.
    • Action Needed: Protect and restore shrubsteppe habitat.
  • Fish and wildlife habitat loss or degradation
    • Threat: Human disturbance may cause nesting failure and nest abandonment.  
    • Action Needed: Protect nest sites from disturbance.
  • Overharvesting of biological resources
    • Threat: Poisoning of ground squirrels; low prey abundance negatively influences reproduction.
    • Action Needed: Consider reclassifying some ground squirrels as protected wildlife; public outreach.

Resources

WDFW Publications

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