Standing in my front yard yesterday, waiting for my golden retriever to fetch a retrieving dummy, I glanced at a bluebird house hanging on a cedar nearby.
It’s made of recycled plastic that would be indestructible if the surrounding woods did not harbor gray squirrels. Unfortunately, the bushy-tailed brigands are frightfully common hereabouts, and they feel it is their privilege, if not their duty, to enlarge the hole leading into any cavity to accommodate their girth.
The bird house, with its ragged, squirrel-gnawed opening, languished in my garage until recently, when my wife brought home a galvanized steel bushing designed to repair such rodent vandalism. It was too small to span the capacious portal, so I mounted a piece of plywood to cover the original surface, screwed the bushing in place and rehung the birdhouse, hoping to attract a late-nesting bluebird couple.
Twenty-four hours later I discovered that a new tenant that taken possession of the house. To my surprise, however, it was not blue and feathery, but gray…and warty. To be specific, it was a gray tree frog.
You might think I would be disappointed by this turn of events. In truth, I’m quite pleased. Bluebirds are fair-weather neighbors, arriving after winter has blown its last gale and departing long before November draws its dreary, gray curtain over Missouri skies.
Gray tree frogs, on the other hand, stick with us all year long. They might not be visible for much of the year, but they are out and about long before the first bluebirds of summer arrive and they can be found beside the porch light on evenings well into October. And when the inevitable warm spell occurs in February, they announce to all and sundry that spring is not far off.
This points up another area where gray tree frogs outperform Missouri’s state bird. Whereas the bluebird’s song is a brief, unmusical mumble, the gray tree frog announces itself with a lusty and remarkably birdlike trill that never fails to make me smile. This “song” is doubly remarkable for its volume, which is far out of proportion to the singer’s diminutive size. I would bet that not one in a hundred people, upon hearing a gray tree frog’s voice at dusk or dawn, ever guess that they are being serenaded by an amphibian, rather than a bird.
My warm, fuzzy reaction to the gray tree frog’s trilling song might have something to do with memories of how they helped me introduce my daughter and son to nature. As noted earlier, these little songsters like to hang out beneath outdoor lights, thanks to the smorgasbord of tasty insects that congregates there.
To illustrate this connection, I used to capture inch-long moths and dangle them, fluttering, in front of the 2-inch long frogs. In moments, the hungry amphibian would grasp the offering between its front legs and jam the dry morsels into their gaping maws with apparent gusto. Particularly large, dusty meals might require extra stuffing and several convulsive gulps to swallow, but I have never seen one of these guys start a meal it couldn’t finish. Watching such outsized morsels disappear into such a small creature is a geek-show that would put the carnival side-show freaks of yesteryear to shame.
Beneath the porch light is definitely the easiest place to find gray tree frogs. When perched in the more natural habitat of tree trunks, their mottled gray color and bumpy skin render them virtually invisible. Knowing this, you could be forgiven for mistaking juvenile gray tree frogs for an entirely different species. Young of the year are a bright – somewhere between lime and grass – green.
In one of those astonishing and inexplicable tricks of nature, the gray tree frog has two species, common and Cope’s. The two are visually indistinguishable, and their ranges overlap extensively. So, you may ask, how do herpetologists tell them apart? If you have a highly attuned ear, you might detect a higher pitch in the trill of the Cope’s gray tree frog. If not, and if you own an electron microscope, you count their chromosomes. The common gray tree frog has precisely twice as many as the Cope’s!
Gray tree frogs are common from the Atlantic Coast westward to Minnesota and eastern Texas. During the day you might be able to locate them on the undersides of wooden decks and lawn furniture. They also like to hide beneath the leaves of potted plants and in crevices of window and door casings. This last habit gets more than a few of them squashed.
They are most active at night and on overcast, rainy days, which apparently make them feel so fine they can’t resist singing. While I’m a little sorry my newly refurbished bird house won’t be hosting bluebirds, I’m tickled to know it is being used by a warty-skinned neighbor who shares my love of rainy days.