Swainson’s Hawk

Buteo swainsoni

The Swainson’s Hawk is a world class traveler, migrating between Argentina and the Western USA. Some birds will breed all the way to northern Yukon in Canada and northeastern Alaska. When they migrate, large groups will gather by the dozens or by hundreds, roosting overnight in some chosen grove. When the morning sun heats up, and thermals caused by rising warm air develop, the roosting birds launch into a slow circling formation and rise to great heights to begin their next step towards their winter or summer homes. Because the spectacle looks like an enormous boiling pot of water, people call this a kettle.

Early in the 2000s, I first learned of these migration events, and the rabid birders who assemble at key locations called Hawk Watches. Most folks thought passes in the mountains along the Mexican border were the only places to gather to watch these and other birds of prey pass by. That changed when Hal Cohen, a passionate hawk watcher from the upper Midwest, moved to Borrego Springs (San Diego County, California) in 2001. There were no organised hawk watches there at the time, but Hal began his own reconnaissance regime. Two years later, in 2003, he discovered a major flyway through the desert, and the local birding community received the benefit of witnessing our own kettles of annual migrating Swainson’s Hawks. In 2012, I attended one such spectacle, and it was quite a show.

Today’s science regards the Swainson’s Hawk as monotypic (i.e. no subspecies).