Saturday, January 18, 2014

Rough-legs on the High Plains

Winter is not the ideal season for crossing the High Plains of North America; strong winds, blizzards and dust storms may pose a challenge for travelers but monotony is the primary threat.  The flat, nearly treeless terrain becomes a brown sheet of dry grasslands and crop fields and encounters with wildlife are generally few and far between.

Yesterday morning, however, I was entertained by a large number of rough-legged hawks as I traveled along Interstate 70; at least 25-30 were encountered between Denver and Wakeeney, Kansas, perched on fenceposts or hovering above the plains, hunting for rodents.  East of Wakeeney, trees become more abundant and the topography is more varied; there, in the mid-grass and tallgrass biomes, red-tailed hawks are the dominant raptors throughout the year.

Rough-legged hawks, named for their feathered legs and feet, are circumpolar in distribution and breed on the Arctic tundra and adjacent taiga.  Before winter sets in, they head to more southerly climes and are found throughout most of the U.S. except for the Southeastern States.  Since they favor open country that mimics their homeland, they are best found on the High Plains and across the basins of the Intermountain West.  Bulky in appearance, they are easily identified by a prominent black tail band and dark wrist patches on the underside of their wings; their plumage is otherwise highly variable.  While many hawks and falcons hover when they hunt (especially on the windy plains), rough-legged hawks are especially inclined to use that technique.