In Our Backyard: Swainson’s Hawk

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The Swainson’s hawk (Buteo swainsoni) is a wonderous bird with quite a range of colours. The best way to identify a Swainson’s hawk is to look for a combination of key characteristics. These include white underwings that contrast with dark flight feathers, light-coloured bellies and a dark chest. When soaring, their long wings are slightly raised into a dihedral. These grey, white, and brown hawks hunt small mammals in flight, or even run after insects on the ground. The Swainson’s hawk is known to spend a substantial amount of their lifespan in the Thompson-Nicola Watershed, primarily breeding in the Thompson-Okanagan Plateau. They have one of the longest migration patterns where their migration begins as far north as Alaska all the way to the south end of South America.

Habitat

The most common places for the Swainson’s hawk to breed are in lower elevation grasslands and agricultural habitats, and the most sightings of this creature have been in Bunchgrass, Ponderosa Pine and Interior Douglas-fir biogeoclimatic zones. Because all of these habitats can be found in Thompson-Nicola Watershed, it is no wonder this area has the highest probability of observation of the Swainson’s hawk.

Being a migratory bird, the Swainson’s hawk moves from southern South America, during their nonbreeding season, and migrates north through the United States all the way to Canada and Alaksa for their breeding season.

Watch this video to listen to the Swainson’s hawk call:

Threats

In BC, the Swainson’s hawk is historically known to be quite abundant, but now their populations are declining due to various threats to the species including:

Loss of Habitat

In the Thompson-Nicola Watershed, the recession of grasslands due to urban sprawl, forest encroachment and agriculture use are one of the main threats to the Swainson’s hawk. Because this habitat is where they spend their breeding season, the reduction of grasslands greatly affects the species and their reproduction.

Use of Pesticides

Another cause for concern for the Swainson’s hawk is the use of pesticides on rodents and insects. These creatures are the hawk’s prey, and when the rodents and insects are poisoned, in turn, the hawk is also poisoned.

Conservation Efforts

The Swainson’s hawk is considered a red-listed, or endangered, species in BC. Swainson’s hawks, their nests and their eggs are legally protected under the BC Wildlife Act. Stewardship and management recommendations for protecting and conserving the Swainson’s hawk are as follows:

  • establish a 60m no harvest buffer zone around nest trees;
  • outside of the no harvest zone, avoid disturbance to active nest sites during the breeding season between April 1 and September 1 and avoid harvesting, salvage, blasting (within 1 km), road construction, helicopter activity (within 500 m) or other prolonged disturbance;
  • maintain mature nest trees such as ponderosa pine, black cottonwood and trembling aspen near foraging habitat located adjacent to Swainson’s hawk nest sites;
  • where possible, avoid road construction through potential Swainson’s hawk hunting habitat (open grasslands and fields); and
  • do not use pesticides or rodenticides near Swainson’s hawk nests or in foraging areas.

Additional Resources