WHY SOME RAPTORS NEST EARLY

      By the end of November every year, in the woods of Lancaster County, Pennsylvania, I hear pairs of great horned owls hooting to each other as the start of their courtships.  And through December each year, I continue to hear the romantic owls back in the woodlands, and see pairs of bald eagles and red-tailed hawks perched together on large, lone trees in local, human-made cropland, or soaring together over that farmland, to which the eagles and hawks have adapted well.

     In January, these three kinds of raptors start adding sticks and twigs to their open cradles in tall trees, in woods in the case of the owls, and in farmland for the eagles and hawks.  Young pairs of each kind might usurp stick nurseries from herons, crows, ospreys, or other pairs of their own kinds, or build new nests.  The cradles of all those birds are big, made of sticks and twigs, and placed in treetops.  I'm sure there is some competition among these larger birds for treetop nurseries.

     During the first half of February, each female of these raptors lays one to three eggs in her cradle.  The females do most of the incubating, while their mates hunt prey animals, or carrion, for themselves and their mates on their nests.  That teamwork between mates of each pair is essential before the chicks hatch, and while they are young, small and can't warm themselves in the cold of early spring, or defend themselves from the predations of crows, other raptors, black vultures or raccoons.  Young owls, eagles and hawks require constant brooding and feeding until they are old enough to produce their own body heat and defend themselves while both parents of each family, at the same time, is hunting food for their rapidly growing youngsters.  

     The offspring of these three raptor species fledge their nurseries by early June, just when young, innocent prey animals are abundant, making hunting those critters easier for the young owls, eagles and hawks.  The winter courtships of these birds of prey; their time of egg laying, the chicks' times of  hatching and fledging ensure that the fledged young will have relatively easy hunting to give them a good start when on their own.  The timing of all that worked out right for the benefit of the young raptors.

     Great horned owls, bald eagles and red-tailed hawks live throughout much of North America.  There is a degree of competition for food among them, though the owls hunt prey mostly at night, while the other two kinds hunt exclusively by day.  

     Many pairs of bald eagles live and nest along rivers and large impoundments, but some pairs hatch young in farmland near creeks.  There they compete for food with the red-tails, some pairs of which move away from the eagles.  Farmland-nesting eagles do catch fish, but also other creatures that red-tails also prey on, such as ducks, squirrels, rabbits and wood chucks.    

     These three kinds of birds of prey are successful rearing offspring in early spring because of their working together to raise their young.  One parent of each pair broods eggs and small young while the other parent hunts for the whole family, until the chicks are older and bigger.  That early courting works out that the young get a good start when they are first on their own.  

           


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