Spring Peepers and Chorus Frogs

     Many a warmer evening early in April in Lancaster County, Pennsylvania I have stood on the edges of shallow ponds and wetlands in moist, wooded bottomlands as darkness closed in around me and listened with awe to the sweet, earnest peeping of male spring peepers, a kind of tree frog.  The air fills with their boisterous, high-pitched peeping, almost to the point of hurting my ears if I am close to those tiny frogs.  And joining that wild, clamoring peeper chorus in certain wetlands are several rising calls that sound like someone running a finger along the edge of a plastic comb, "crreeeeeekk".  Those raspy, but beautiful, trills are emitted by several male chorus frogs calling at once.  Male peepers and chorus frogs call females of their respective kinds to join them in shallow water to spawn their many eggs.  And I have always enjoyed hearing their intriguing, inspiring  choruses, their bit of the wild in our civilized part of the world, their remnant of the amphibian age of long ago, in this area during April evenings.  Some people, including me, go out of their way on April evenings to hear these wonderful, pleasing harbingers of the vernal season.  And I have often stayed in the wetlands until dark when I was finally engulfed only by the damp coolness of the air and the wild, unceasing shouting of the romantic peepers.    
     Spring peepers and chorus frogs have several characteristics in common, partly because they are both in the Pseudacris genus.  Both these related species are mostly nocturnal and have big eyes for better sight at night,  They are both a little over an inch long at maturity and mostly brownish for blending into the wetland surroundings they often share.  Those are reasons why they are mostly "voices in the wetlands" where they eat invertebrates, spawn, and hide during the day and through cold weather.  Few people ever see them.
     Both these tree frog species have extensive ranges in eastern North America, including here in the Mid-Atlantic States.  In fact, these frogs are in North America exclusively.  Both are "winter" frogs in the Deep South where they spawn on warmer, rainy days anytime from November into winter.  But in the north they are harbingers of spring, calling and spawning from late March, sometimes even before all the ice has melted, through April.  Male peepers and chorus frogs both sing from protective clumps of grass emerging from the inches-deep water, and the peepers also peep from emergent shrubs and trees.
     Spring peepers range from Hudson Bay to northern Florida and west to the Mississippi River.  They are tan with a darker X on their backs.  The clear, loud peeping of the males is sometimes followed by a short trill.  A peeper chorus from a short distance sounds like a jingling of small bells.  Their delightful peeping is the best part of this species to us humans.
     Chorus frogs as a group of several closely related species live in the American mid-west up to Hudson Bay.  And they live along the forested Appalachian Mountains, the New Jersey Pine Barrens and other woody areas in the eastern United States.  For the most part, they are yellowish-brown all over with elongated, irregularly-shaped, dark brown spots or short stripes.  But, like the peepers, it's the males' trills in spring that are the best part of this species to us.         
     The reader might like to try listening for spring peeper and chorus frog choruses during evenings this winter or spring, or succeeding ones, depending where you live.  Choruses start in winter in The South because of warmer average temperatures that allows these cold-blooded creatures to be active.  But as spring progresses north, the spawning choruses of these frogs, and other frog species, begin when temperatures rise in each part of the country in turn.