A Chorus of Frogs

by

This pond is nothing grand. Just three feet across and two feet deep, it was bought years ago and buried in the ground. This is no landscape designer’s vision. Surrounded by Autumn ferns, English ivy, wild violets, jack-in-the-pulpits and sweet woodruff, it is, however, a frog’s idea of paradise. Generations have reared their young here and each year during warm weather I enjoy the free concerts they hold forth.

For many people, spring begins with bird songs and the first green tips of hyacinths and daffodils as they break through the garden’s soil. For some of us, it’s the sound of Spring Peepers rising from water-filled ditches and wetland edges. All winter they have hibernated beneath the leaves, protected by an internal sugary antifreeze peculiar to frogs. As the weather warms, they rouse from their frozen torpor and begin to sing.

These diminutive Spring Peepers are the first to sing each spring in the eastern United States and Canada. They seldom climb very high and in early spring their sometimes deafening chorus keep folks nearby awake. As long as the temperature remains above freezing, they sing day and night. Calling males may form duets or trios and sing for one purpose only, to attract a female. This story is repeated again and again all over the country.

When the warm rains of spring and summer arrive, and all the way through early autumn, there is an explosion of activity in the amphibian world. Frogs and toads emerge and join in chorus. They produce all manner of sounds — croaks, peeps, beeps, glubs, shrills, shrieks, chirps and trills and experts can identify which species just by listening to their sounds. Sigurd F. Olson in his book The Singing Wilderness said, “This is a primeval chorus, the sort of wilderness music which reigned over the earth millions of years ago... one of the most ancient sounds of the earth...”

Frogs and toads produce sound by passing a stream of air from their lungs over the vocal chords during expiration. One or more vocal sacs inflate while a call is made, helping broadcast the sound over a large area. Some species’ calls occur in rapid succession while others make single pulses of sound with pauses between. Producing calls expends enormous energy, increasing the frog’s metabolic rate ten to 20 times more than a frog at rest.

Frogs are amphibians, the term coming from a Greek word meaning two lives, and in a sense frogs experience two lives. First as tadpoles that breathe with gills and eat algae, and then they develop legs, lose their fish-like tails and move onto land as adult frogs. It is a fascinating transformation and because of this, the mention of frogs appears in many cultures.

Ancient Egyptians, Greeks, and Romans considered frogs symbols of fertility, and Egyptians actually worshiped them. The Old Testament took umbrage to the idea, and a plague of frogs was sent as punishment to an unrelenting pharaoh. In China, they were associated with healing and good fortune in business. During the Dark Ages, frogs were associated with witches and their evil brews. The Brothers Grimm wrote about The Frog Prince, who was magically transformed into a handsome human prince with the kiss of a fair maiden. Toads are often not distinguishable from frogs in popular culture, but UK author Kenneth Grahame portrayed Mr. Toad as a wealthy, likable and popular, albeit selfish and narcissistic, comic character in his 1908 novel, The Wind in the Willows.

There are currently 97 native species and four introduced species of frogs and toads in North America. Both are members of the order Anura, which is Greek for tailless. They are classified into nine family groups, each with their own unique characteristics or behaviors. Several are native to our region. What species you may have on your property depends on where you are.

All amphibians need moisture to survive. Rather than drinking water, they absorb it through their skin. Although many live in watery environments like ponds and wetlands, others wander off to live in woodlands or grassy areas. To stay moist, they seek out damp hiding places in tall dew laden grasses, under leaves, under logs and debris piles.

Frogs and toads are a vital link in the natural world’s food chain. Their spawn provide meals for dragonflies, fish, mammals, reptiles, and birds. But as adults they do their share of eating too, feeding on mosquitoes, flies and aquatic invertebrates. The larger frogs and toads eat small fish, other amphibians, reptiles and even rodents. The Audubon Society referenced one recent study that found that a healthy frog population removed more than 50,000 insects per acre per year. Not bad for insect control!

So what is the difference between a frog and a toad? In reality, very little. The fact is, frogs and toads fall under the same taxonomical classification. To further muddy the pond water, all toads are frogs but not all frogs are toads! So how do you tell the difference?

Most frogs have long legs and smooth skins covered in mucus. Toads generally have shorter legs and rougher, thicker skins studded with warts. However, some frogs have warts, and some toads have smooth, slimy skin, which leads many biologists to argue over what’s what. There are some clues, however, that help define the difference between the two. Frogs lay their eggs in a cluster that resembles a bunch of grapes, while toads generally lay their eggs in long strands. The male frog will often hover nearby, guarding its eggs, while toads abandon their spawn, relying on its offensive secretions to discourage their predators.

In fact, both toads and frogs have glands that give off secretions. These glands are located primarily along the head and back, but the kind of secretions they give off can vary from merely obnoxious to downright poisonous. These secretions may cause predators to drop them and teach them to avoid that species in the future.

Frogs and toads are cold-blooded and, therefore, unable to regulate their body temperatures. When they get cold, they become inactive, so most of their activity is limited to spring, summer and early fall. During the day or at night if the weather has been unseasonably dry, they take shelter in moist places. Frogs will retreat to water or settle under rocks or leaves. Toads will often retreat to burrows they dig themselves or inherit from others. So, it is mainly in the early dawn hours, at dusk or after dark that they are most active and their songs fill the night. Sadly, there are fewer calls now than there have ever been.

CANARIES IN A GLOBAL MINE

According to scientists in the history of life on earth, there have been five mass-extinction events in which the majority of then-existing species perished. The most recent occurred 67,000,000 years ago that snuffed out the lives of the dinosaurs. We are now in the midst of a sixth extinction, this one the direct result of human destruction and alteration of habitats worldwide. Amphibians are disappearing at unprecedented rates. In some locations, entire populations have disappeared in a year’s time. Oddly, some of these declines have occurred in our best protected natural areas. Climate change, an increase in ultraviolet radiation, invasions by non-native species and toxic pesticides are all suspects.

So, what can you do to help their plight? The simple actions you take in your own backyard habitat can help stem the tide of these growing losses. Create good habitats for frogs and toads: moist hiding places, shallow ponds, plant cover, leaf litter and flowers that attract insects for them to feed upon. If you have a small pond, do not stock it with fish that will feed on frog eggs and tadpoles.

Create hiding places by building small rock or brush piles. Make a toad home by sinking a flower pot onto its side into the garden soil or landscape bed. Fill it partially with soil and place the opening facing north to shade it from the sun’s rays. Avoid using insecticides, which kills off vital food sources. And watch where you walk! Back at my frog pond, the male and female Green frogs have settled in for the summer, ensuring the next generation of frog songs. There’s good news for the rejected suitor as well. He has found a mate in a small stone basin filled with water under a large hydrangea. The shrub provides shelter and attracts an insect feast. It’s dusk, and the chorus in both are warming up.