BROODING IN SNOW

      Bald eagles, great horned owls and red-tailed hawks are big feathered predators that begin nesting by January, into early February in the Middle Atlantic States.  They start their breeding cycle that early so their youngsters are on their own in June when the prey species of each kind of raptor is most abundant and vulnerable, which gives those inexperienced, unskilled immature young a good start to their independence.  Even so, some young raptors starve to death before they develop adequate hunting skills.  

     Each mated pair of eagles, horned owls and red-tails forms a tight bond to raise their progeny together, which is necessary in late winter and early spring to keep their offspring safe from other creatures, and warm in open, stick cradles in tall tree tops and exposed, human-made structures that some of these adaptable raptors use as nurseries.         

     To protect eggs and small young, each female of all these species constantly broods them, while her mate hunts for her and himself.  Some males relieve their mates on their stick cradles.  These dedicated parents even brood eggs and young during snow storms when the incubating birds get partially covered with snow.  On-line, I've seen some brooding raptors partly covered with snow, with only their heads and necks poking out of it.  

     These large, early-nesting raptors are stately, especially when perched high in trees.  And since the popular use of live cameras on raptor nests and posting those views on computer screens, viewers can experience these raptors up close, without those brooding birds knowing they are being observed.  

     Females of each of these species lay up to three eggs per clutch and raise only one brood a year, which is enough to keep their populations at healthy levels.  Not many predators get through the defenses of the parent birds to eat their chicks.  

     Each of these females lays an egg every few days and begins brooding when the first egg is laid.  The result is the young hatch a few days apart, which means the oldest chick in a brood is substantially bigger than the last-hatched baby.  When prey is plentiful, all chicks are well fed.  But if prey is scarce, the oldest youngster, being larger than its siblings, will get most or all food delivered to its nest by its parents, resulting in the third baby, and maybe the second one, too, dying of starvation.  That is a harsh, built-in birth control system.  When there is not enough prey animals to feed all the young, that indicates there will not be enough food if the second and third young raptor did mature to independence.  

     Bald eagles live and nest along waterways, impoundments and farmland here.  Many of these eagles winter downstream from hydroelectric dams on the Susquehanna River where water that falls through turbines wells up downstream, where its turbulence keeps it ice-free and makes fish available to eat.

     The majestic bald eagles catch larger fish, ducks and other creatures they can handle.  But they also scavenge those critters, as well.  And they scavenge dead farm animals discarded in fields.           

     The stately great horned owls here reside in woods, groves of tall evergreens, and older suburban areas with their many tall deciduous and coniferous trees.  Pairs here court in December, when many people hear them hooting to each other, mostly at dusk and dawn.  These owls mostly hunt rabbits, squirrels and other kinds of rodents at night.

     Red-tailed hawks are day-time counterparts of horned owls in this area.  These handsome hawks prey on the same critters the owls do, but during the day.  Red-tails specialize in catching gray squirrels in woods and suburbs, and brown rats in farmland.

     These magnificent, hardy raptors in southeastern Pennsylvania, and elsewhere, are known for nesting early in the year, even when cold prevails and snow flies.  Each pair of these species must work together to raise young in those conditions.  And they must help each other brood and feed their progeny, and fight off would-be predators to raise their young to independence.