Species Profile

Quick Facts

  • Nearly 95% of California’s remaining Swainson’s hawk population is in the Central Valley.
  • Swainson’s hawks are migratory. In the winter, they migrate as far as 14,000 miles from breeding habitat in California to southern Brazil or Argentina.
  • Groups of soaring or migratory Swainson’s hawks are referred to as “kettles.” Groups of hunting Swainson’s hawks are referred to as “boils.”
  • The oldest wild Swainson’s hawk on record is 24 years old.
Status

The Swainson’s hawk has been listed as a threatened species in California since 1983, after breeding populations experienced a 90% decline between 1900 and 1979.

Species Information

Historic populations of Swainson’s hawk in California reached over 17,000 nesting pairs. But by 1980, due to wide-scale development and loss of habitat, populations had declined dramatically, and only an estimated 375 breeding pairs remained. Swainson’s hawks are making a comeback - in 2005, a statewide survey estimated about 2,000 breeding pairs across California.

Working lands as high-quality habitat

Habitat loss remains a major threat to the Swainson’s hawk. As the landscape has changed in the Central Valley, Swainson’s hawks have adapted. Today, they use pasture and fields of crops as prime foraging habitat, and they nest in trees scattered within agricultural landscapes.