An Annual Reproductive Cycle

     Each species of wildlife reproduces about the same time each year, creating an annual reproductive cycle, including here in the Middle Atlantic States.  We could begin looking at that cycle during any month of the year, including the end of July when courting male crickets, grasshoppers and katydids stridulate their wings, or wings and legs, together to make chirping, chanting or trilling sounds we hear most every evening from late July until heavy frost kills those six-legged fiddlers in October.  The purpose of those chants and trills, like all courtships, is to bring the genders of each species together to reproduce themselves while they can.
     During August in this area, annual cicada grubs crawl out of the ground where they lived and sucked sap from tree roots.  Each grub crawls up a tree.  At some point, the back of its exoskeleton cracks open and the mature cicada crawls out.  When its wings are pumped out, the grub flies off in search of a mate.  Male annual cicadas have flaps under their abdomens that they vibrate to make those whining, pulsing sounds we hear on August days and evenings, which attract mates to them for breeding.
     Elk or wapiti begin their courtships during September and into October.  Magnificently big bulls bugle wild, piercing challenges to each other rather than fighting by using their antlers to push against each other to test how strong their opponents are.  Each big bull collects a harem of cows that he tries to keep away from other bulls.  And he will fight other bulls when he has to.  About a thousand elk live in a few, mostly forested counties in north-central Pennsylvania.
     White-tailed deer court from about the middle of October to mid-December.  Again the majestic bigger bucks shove each other with their antlers to determine dominance to mate with the does.  And white-tails are less cautious during the breeding season, making them hazards on the roads to us and to themselves.     
     As white-tailed deer are reaching the peak of their courtships around the end of November, great horned owls are just beginning theirs.  We now begin to hear the partners of each pair hooting back and forth to each other at dusk and dawn.  Their courtship hooting continues most every dusk and dawn through December. 
     Horned owls take over the stick, platform nests of hawks, crows and herons in woods, and older suburban areas with their many tall trees, especially conifers.  There they attempt to raise one to three chicks.  And by starting to court in mid-winter, these owls raise their young to independence by early June when prey animals are abundant and often easy pickings. 
     Red-tailed hawks and bald eagles in this area begin their courtships in December and continue through January.  Now one can see pairs of each majestic species together on nest trees and performing intriguing courtship displays in the air.  And one can hear them calling to each other as they rebuild the stick nurseries they used last year.
     During warm afternoons in February, male small birds of permanent resident species, including tufted titmice, northern cardinals, mourning doves and song sparrows, begin singing to establish nesting territories.  They have watched the daylight each succeeding day increase, which stirred their hormones and made them start singing.  Cold weather or a snow storm will stop their singing for a few days.  But they start again when the weather warms.
     During heavy or prolonged warm rain sometime in March, wood frogs and spotted salamanders come out of hibernation under the leaf cover on forest floors and make their ways to nearby pools of rain and snow melt in depressions on the leaf-covered forest floor.  Male wood frogs croak hoarsely to attract and direct females of their species to the pools for spawning of eggs.  The salamanders, however, are silent, but males and females find each other for breeding.  With their spawning completed within a few days, wood frogs and spotted salamanders retreat to their shelters under fallen leaves on forest floors, leaving their young to hatch and raise themselves.
     And every evening, except stormy weather, during March and through April, male American woodcocks court nearby females.  At dusk, each male flies out from a bottomland woods to a spot of bare soil in a field where he stands upright with his beak on his chest and "beeps" about a minute.  Then he takes off in spiral flight upward while his wings whistle rythmically.  At the top of his spiral he vocally sings several series of four notes each that seem to tumble to the ground, followed by the woodcock himself to the same bare spot or another one in the field.  Each male continues his series of courtship flights until interrupted by receptive females or hunger.
     To see those woodcock courtship flights, stand in a field by a woods known to have woodcocks in it and face the sunset.  That way you can see the woodcock silhouetted in flight.
     By the end of March, male spring peeper tree frogs and American toads peep and trill respectively.  Male peepers continue peeping each evening through April, but the toads only trill for a couple of weeks.  Their ear-splitting racket, which is pleasing to many outdoor people eager for signs of spring, again joins the genders of each species for spawning in ponds and marshes.
     Also by the end of March, American robins, eastern bluebirds, red-winged blackbirds and other kinds of hardy birds are beginning to sing to establish breeding areas.  We are particularly fond of  the songs of these birds because they represent, undeniably, that spring and warmer weather have arrived.
     By the end of April and through May, June and early July, males of several species of small birds that wintered in Central and South America are singing to establish and maintain nesting territories, and to attract a female of their respective species.  Thrushes, warblers, vireos, orioles and tanagers are some of those tropical bird species come north to raise young.       
     As small birds wind up raising their second broods of the year by late July, male crickets, grasshoppers and katydids begin their fiddling to attract mates to them for another reproductive cycle.  And now we are a bit more familiar with some of the creatures in the Middle Atlantic States that engage in courtships we can experience.  Those courtship displays make our lives a little more interesting.