A Banded Visitor from the North: Tracking the Journey of a Rough-legged Hawk
Last week while out birding in the fields, I spotted a striking raptor perched along a treeline. A nice dark morphed Rough-legged Hawk (Buteo lagopus). These Arctic-breeding hawks are always a winter highlight for birders across much of the U.S. and southern Canada, but this sighting came with a bonus: a visible leg band.
I got lucky and managed to photograph the band clearly enough to read its number. Through a few quick emails and messages contacts, I eventually found out that this hawk was originally banded in March 2021 by the Simcoe banding group as an adult of at least four years old at the time. The hawk was found more than 900 km north of where it was first banded. That makes this bird at least eight years old today, possibly older. It’s a remarkable example of longevity in a wild raptor species and a testament to the power of citizen science and bird banding programs.
The Rough-legged Hawk: A Tundra Nomad
The Rough-legged Hawk is named for its feather-covered legs, a feature shared only with a few other raptors, like the Ferruginous Hawk and the Golden Eagle. This adaptation helps them survive in the frigid environments of their breeding grounds: the Arctic tundra.
These hawks are long-distance migrants. Each autumn, they journey thousands of kilometers southward, often reaching the northern United States and central Canada. Their wintering range includes open country—farmlands, grasslands, and marshes—where they can hunt small mammals like voles, lemmings, and mice.
Come spring, they head north again, back to the remote Arctic where they breed in cliffs and tundra habitats. This impressive round-trip migration can total over 5,000 kilometers annually.
Tracking Time Through Bands
Bird banding is one of the oldest and most informative tools in ornithology. By marking individual birds with unique identifiers, scientists can gather invaluable data on migration patterns, lifespan, survival rates, and population trends.
This particular hawk was banded in the spring of 2021, but because it was already an adult of at least four years at the time, we now know it has successfully completed several migrations across North America. At eight years or more, this bird is on the older side for Rough-legged Hawks, though they can live longer—especially in the wild, where individuals over 10 years have been documented.
Each recovery like this adds a puzzle piece to our understanding of avian life histories and long-term changes in migration behavior in the face of a changing climate.
Light and Dark: Rough-legged Hawk Color Morphs
One of the more fascinating aspects of the Rough-legged Hawk is its polymorphism. Individuals come in both light and dark morphs. Light morphs have pale underparts with contrasting dark belly patches and carpal patches on the underwings, while dark morphs are chocolate brown overall with subtle markings.
These morphs are genetically determined and occur in both sexes. Dark morphs are more common in the western parts of their range, and their adaptive significance is still a topic of research. Some scientists speculate that darker plumage may provide advantages in certain habitats or hunting conditions, though both morphs seem to coexist successfully across the species' range.
A Moment of Connection
Spotting this banded Rough-legged Hawk reminded me of how connected we all are through nature—and how much we still have to learn. Every time a bird is banded and later resighted, it contributes a thread to a much larger story, one woven by biologists, birders, and enthusiasts around the world.
As spring migration continues, keep your eyes to the sky—you never know what secrets a passing bird might carry.
Laurent Bédard
