Swainson's Hawks on Their Way North

By Dan Weisz

All photos by Dan Weisz

In Southern Arizona, we see large numbers of Swainson’s Hawks as they migrate through every spring and fall. Some Swainson's remain in southern AZ during the summer, but the migrating numbers are always overwhelming. Swainson’s Hawks are close in size and shape to the more common Red-tailed Hawk. They are longer and narrower with more pointed wings than Red-tails have. The plumage colors of Swainson's are so variable, making these great birds to find. I recently passed two fields in Marana where upwards of 100 Swainson’s had settled in at the end of the day.

Swainson’s Hawks are long-distance migrants. During the summers, Swainson’s Hawks live in much of the western states and up into Canada and Alaska. During the winter, most of the Swainson’s migrate all the way down to Argentina. Now, they are on their way back. That’s a heck of a journey!

Swainson’s Hawks are birds of open country. They are large hawks with broad wings and short tails. Swainson’s Hawks can be found perched on any tall feature in that open country including short shrubby trees. They can also be found standing on the ground in areas that have few proper perches.

One of the things that makes Swainson’s Hawks special is the wide variability in color and plumage from bird to bird. The bird below was perched on a large berm very close to the bird above. While the two birds look similar, the one below has white above its bill and a much whiter throat than the first hawk did.

During breeding season, Swainson’s Hawks feed on the Three “R’s” of raptor diets: rodents, reptiles and rabbits. When it is not breeding season, the diet of Swainson’s Hawks switches more to insects of all kinds. Because Swainson’s feed on insects during their migration, you can often find them on the ground in farm fields like this one. After flying all day, they settle down to feast on the insects in the fields.

There was one immature Swainson’s Hawk that we could see. Swainson’s take three years to achieve their adult plumage. The white head is an easy indicator of this bird’s age. He was looking back towards the setting sun.

Immature Swainson’s also have lighter eye color than adults do. This bird’s iris is yellow rather than the darker color of an adult’s. Its breast is also a patchier pattern than an adult’s would be.



It is always fun to run across Swainson’s Hawks in numbers during migration season and this group made our day’s adventure even more special.

Dan Weisz is a native Tucsonan and retired educator who enjoys birding, being in nature, and taking photographs.