Spring peepers are tiny frogs with a big job—announcing the start of spring.
It Might Get Loud
You have grown weary of the cold, the gray, the barren branches, the heap of winter coats and boots jumbled by the front door. You long again for warm days and short sleeves and the fresh scent of growing things. And then, one evening, driving past some low-lying fields flooded by recent rains or even a long, marshy ditch paralleling a country lane, you hear it and your heart leaps with joy: It is the unmistakable call of spring, the cheerful, chirpy chorus of the spring peepers.
“Peepers have traditionally been considered the iconic harbingers of spring,” says Mike Hayslett, resident naturalist at Sweet Briar College and director of the Virginia Vernal Pools Program. “They tell us we’ve survived another winter and spring is here and times are going to get better.”
Hayslett, who not incidentally can produce a remarkably apt imitation of the call not only of a single peeper but of an entire chorus, explains that spring peepers are one of the first amphibians to emerge in spring thanks to a neat trick of physiology. They are among a small, select group of amphibians with the ability to endure literally being half (or more) frozen. Peepers use glucose to prevent their cells from being damaged by the freezing, and also manage to thaw evenly, inside and out, at the same rate. With this capability, peepers survive in a geographic range that extends north, well into Canada, and they also can pass the winter close to the water surface, ready to emerge at the first hint of lengthening days and spring warmth.
By starting so early, peepers can take advantage of shallow, short-lasting, fish-free wetlands known as vernal pools, which warm early and may go nearly or completely dry by mid-summer. These provide a hospitable environment where peeper eggs can hatch into tadpoles that in turn mature into froglets and leave the water before summer begins. “The peepers’ strategy is to reproduce early, while it’s cold, so their offspring can develop and get out of the water before it’s full of competitors and predators,” says Hayslett.
Of course it all begins with the distinctive song, the call to prospective mates, which in early spring becomes a growing chorus that, in some areas, can swell to thousands. “Typically by early March you begin to hear the peepers actually chorusing,” says Hayslett. “If you walk down into a marsh in the night in the middle of this, the decibel level can be absolutely deafening.”
If you listen closely, you can note as well that the males strategically time their peeps to call between their neighbors’ notes, each trying to nab its moment to catch the attention of the females. “Though when it gets into these choruses where there are hundreds and hundreds of males calling, it’s beyond me how the females distinguish one male from another,” says Hayslett.
The males also have another vocalization you can sometimes hear, Hayslett adds. “It’s a ‘You’re getting too close to me’ warning to another male, a kind of trilling call, like running your fingernail over a comb.” If the encroacher fails to heed the warning, “they can get into it,” says Hayslett. “They’ll wrestle each other.” A pretty amusing image, given that these frogs run roughly the size of a thimble.
Indeed, but for their raucous spring chorus, peepers could easily go unnoticed. Not just tiny, they also dress in variations on the key of camouflage—all grays and greens and browns, which allow them to blend nicely with their preferred surroundings of leaf litter, marshy grasses and underbrush. In the event, however, that you should actually come across one—perhaps the next time you happen to be lying prone in a wet ditch on a spring evening—you will know it by the rough “X” marked on its back, inspiration for the peeper’s Latin name, “Pseudacris crucifer.”
Peepers are known by a colorful range of regional nicknames, from “pinkletinks” on Martha’s Vineyard to “pee toots” along the southern Blue Ridge. At Mountain Lake resort in Pembroke, Virginia (yes, where Dirty Dancing was filmed), there’s a Pee Toots lounge. Whatever name they go by, however, they’ll always mean one thing. Spring.