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Night critters provide a musical interlude
Frogs, toads and insects fill the air with relaxing sounds
By Gary Clark | July 22, 2011
Photo By Kathy Adams ClarkSouthern leopard frogs utter a quick series of hoarse chirps followed by a series of scratchy-sounding, drawn-out croaking sounds.
During summertime walks after sunset, Kathy and I listen to the echoing chorus of nighttime critters. It's not as musical as the dawn chorus of songbirds, but it's no less enchanting.
Identifying night critters by their songs, however, is more challenging than identifying birds because evening critters often are only heard, not seen — unless you have a good flashlight.
This year's unprecedented drought has dampened the voices of many evening critters, especially insects that aren't breeding in the profusion they do during wet summers. The scarcity of water holes, muddy ditches and quiet streams also makes the sounds of frogs and toads a bit scarce.
Frogs and toads enchant me the most. The southern leopard frog, for example, is a 5-inch-long greenish frog with blackish spots on its back. It utters a quick series of hoarse chirps followed by a series of scratchy-sounding, drawn-out croaking sounds. Think of a child scratching on an inflated balloon.
The narrow-mouthed toad is a small, plump, 11/2-inch-long creature with a ruddy or gray body and pale stripes on its sides. Its song is easy to detect because of its long, drawn out, strident, baritone buzzing sound.
Frogs and toads utter songs much in the way birds do, by passing air through the larynx. They amplify songs with vocal sacs in the throat or mouth. In some species, the amplification comes through enlarged mouths similar to the body of a guitar amplifying sound.
About 42 species of insects also sing across the state. The most common are cicadas, which drone in long, dry buzzing zeee-zeee-zeee songs during the day and at sunset.
A robust critter with long wings, the cicada is not a locust, as is commonly assumed from the eerie exoskeleton it leaves stuck to twigs and tree trunks after emerging from the nymph stage.
Cicadas utter their song not with vocal apparatuses but with organs called tymbals containing ribbed structures that vibrate to create the droning and sometimes deafening buzzing sounds.
Crickets, such as the field cricket, hatch in the spring and start a vigorous song in mid-July that will last until the first frost in autumn. Mostly dark brown, the field cricket utters unmistakably clear, loud, repetitive trills.
"Singing" insects, such as crickets, utter sounds called stridulations by rubbing the edge of one forewing called a scraper against a hard bumpy surface called a file on the opposite forewing. The resulting resonances come out as trills, buzzes or chirps.