Hunting Strategies of Cropland Hawks

     Seven kinds of hawks winter in Lancaster County, Pennsylvania's farmland, at least part of some winters with some species.  All those diurnal raptors, adapted to hunting in open habitats, hunt smaller critters in cropland.  And all of those hawks, including red-tailed, rough-legged, American kestrels, merlins, peregrines, northern harriers and Cooper's, perch on roadside poles and lone trees in the fields to rest, digest prey and watch for more victims.  There they are spotted from country roads.  And each raptor species also has a unique way to hunt prey, other than perching, a strategy to cope with hunting in treeless, or nearly treeless, human-made habitats, as well as natural ones.
     Red-tails, with the adults' striking brick-red tails, nest locally and watch for prey by circling high in the sky on wind, or thermals of heated, rising columns of air that hold the hawks aloft.  When prey is spotted, they dive swiftly in hopes of catching it.
     Larger than American crows and about the size of red-tailed hawks, rough-legged hawks raise young on cliffs on the treeless Arctic tundra, but drift south for the winter.  Rough-legs hover into the wind on powerfully beating wings to maintain an aerial position as they watch for lemmings on the tundra and mice in the Lower 48.  That hovering is a way to identify this species.
     The pretty, dove-sized American kestrels nest locally.  And they stand on roadside wires, and hover into the wind on rapidly beating wings as they scan the ground for mice.  They hover a few seconds while watching for prey, soar ahead a little, and hover again, continuing that strategy time after time.  Kestrels can be identified by their size and hovering.
     The related merlins and peregrines are swift, power flyers, a technique designed to chase down feathered prey in the wide open spaces those two raptors are adapted to.  The highly-maneuverable Merlins, flying close to the ground, catch horned larks, sparrows and other kinds of small birds in open habitats, including farmland.               
     Peregrines snare shorebirds, pigeons and ducks in straight-out, swift flight close to the ground.  But these falcons also dive up to 180 miles per hour from high in the sky on prey birds and hit their victims with their chests in mid-air.  Those impacts either stun or kill the victims that tumble to the ground.  But the peregrines swing around and catch their victims in mid-air and fly with their prey to a rocky perch to ingest it.   
     Northern harriers are identified by their long wings, white rumps and method of hunting.  Hawks of this species pump slowly into the wind and close to the ground as they look and listen for mice and other small prey in marshes and fields.  When they come to the end of the habitats they are hunting over, they swing around low with the wind and soar back to the starting point where they again power into the wind close to the ground in search of prey.
     Cooper's hawks are woodland raptors that recently adapted to hunting in open country.  They have short, rounded, but powerful wings, and long, steering tails for chasing birds in the woods.  They use their speed of flight in chasing down and catching rock pigeons, mourning doves, starlings and other medium-sized birds in the fields.    
     These hawk species developed various strategies for hunting in open habitats with few perches.  Some hawks hover into the wind, others fly swiftly, and one kind cruises into the wind low to the ground.  These are just a few of the innumerable adaptations life makes to survive on this planet.
Life on Earth is unbelievably wonderful.