OTTAWA CITIZEN (Ontario) 08 July 06 The danger of a fading chorus
Modern farming practices and unchecked suburban expansion threaten to silence a frog's spring song, writes Janice Kennedy.
It happens each year during the cool nights of early spring. When the pools of standing water are still thinly crusted with ice in the soggy fields and meadows just outside Ottawa, a tiny frog decides the time is right to find a mate.
A tentative soloist, he puffs up the vocal sac under his chin and starts singing his unique song, a krr-eee-k that sounds like a finger running down the teeth of a plastic comb. Then a wonderful thing happens.
In the spaces between his krr-eee-ks, a second little guy joins in, his contribution forming a perfectly timed duet. Another duet starts up, then another and another. Pretty soon, as frogs all over the meadow sing their little vocal sacs out, the crisp nighttime air is bright with the hillbilly hootenanny of small male amphibians on the make.
The chorus frogs are at it again.
"If you listen to a chorus," says David Green, one of Canada's leading herpetologists, "it's possible to hear all the frogs, because they all want to be heard. It's not a wall of sound. It's got a structure, and it's really very, very organized." Mr. Green, a McGill University professor and director of the university's Redpath Museum of natural sciences, has spent a lifetime listening to frogs and learning their habits.
"All the animals try to be heard in their little calling space. You can hear the duets. It's not random at all."
The Ottawa area is one of the natural homes to the pseudacris triseriata, also known as the striped chorus frog, the western chorus frog and even the western striped chorus frog. ("Western" is misleading, though, since it refers to the western edges of the animal's geographic home, from the East Coast toward the continental centre. It does not refer to the continental West.)
The tiny brownish frog with the dark stripes -- so tiny it could sit on a toonie -- has long been a comfortable resident of the grasslands and swampy areas just outside the urban core of
Ottawa-Gatineau. No fancy lakes or cottage country for him, thank you very much. A nice damp field will do just fine.
The trouble is, the damp fields are disappearing. And so are the striped chorus frogs.
Modern farming methods and suburban development are to blame, says Mr. Green. "The older methods of farming were actually kind of good for a number of species -- open-meadow species like meadowlarks, bobolinks, chorus frogs. The modern farming practices are not so good."
Modern methods, which include the use of pesticides and chemical fertilizers, do not encourage healthy frog colonies. Nor does the unchecked suburban expansion that reclaims wetlands and covers them with houses and asphalt.
In Canada, the striped chorus frogs are still fairly numerous in southern Ontario, but they are diminishing in this area and through the St. Lawrence Valley, including areas near Montreal.
"In Boucherville," notes Mr. Green, "a nice little population of chorus frogs is now gone -- gone to housing development. That's what happens. More and more sprawl takes its toll."
The species is considered at risk in these diminishing areas. In fact, a scientific research project has been set up to monitor frog populations in Gatineau Park through a series of listening stations.
Monitor frogs? Why should we care?
For all kinds of crucial reasons, says Mr. Green, who has been fascinated with the creatures since his boyhood in Vancouver. He started out loving dinosaurs at age three, graduated to snakes at six and found his life's calling at 10.
"When I was 10, I caught a toad -- a Western toad -- and that was that."
An abundance of frogs is a sign of a healthy environment, he says. "They serve a number of purposes. The utilitarian purpose is that they are small insect-eating predators, so they consume enormous numbers of insects, and in turn, they're eaten by other things in great abundance.
"Their place in the natural food web is extremely important. They are food for a great many other animals, and they are predators for a great many other things."
Disrupt the natural food web, he says, and the entire system alters in undesirable ways. "You've got more insects, fewer larger predators and the balance shifts." When we alter the way nature works, he says, we create an unknown future with a potentially nightmare scenario.
"We just don't know. We have some general ideas about what happens when you take apart food webs, but the consequences are unpredictable -- although not good. And they're different, in ways you don't know and can't plan for, in ways the economy isn't set up to cope with. Whatever happens, it's going to cost a lot of money."
Mr. Green says the environmental alarm bells about frogs of all types started going off toward the end of the 1980s. One of the more infamous disappearances around that time was that of the Golden Toad of Costa Rica, now extinct. In North America currently, "the Wyoming toad is hanging on by the tips of its toes."
Numerous other species are seriously threatened, he says, and in each case, the disappearance or extinction can be traced to a lost or altered habitat.
The striped chorus frog that has long called Ottawa-Gatineau home is now facing a similar threat.
Its disappearance would be a real shame. The little creature, which likes to climb grasses and stalks with its sticky padded fingers, does its bit for nature's balance and even provides an engaging touch of enigma, too. After they sing their mating song in spring and settle down with their families, they are no longer seen or heard. Summertime is not their time.
"They tend to spend most of their time underground. We don't really know very much about what they do in the summertime. We have no clue. It's not the only frog that we have no clue about, but around here it's the frog we have the least clue about. It's a mystery frog."
But before it disappears, it fills the springtime air with its haunting song. That's the other important reason to care about frogs, says Mr. Green. "People like them. They're part of the landscape. What would the world be without frogs to sing in the springtime?"
A diminished place, clearly. As long as their annual chorus continues to echo across marshy fields, the small striped creatures of this region are a sweet reminder of the poet Robert Browning's timeless observation: For the time being, God's still in His heaven. And all's right with the world.
The danger of a fading chorus