Seventeen years of counting toads and frogs



GENESEE COUNTY — Odds are, unless you’re a 10-year-old boy or a herpetologist, you haven’t thought a lot about frogs lately.

Fortunately for the frogs, the Dept. of Natural Resources has, and at the end of March or in early April, will launch its 17th annual frog and toad survey across the state.

Designed to serve as a rough indicator of the state of Michigan’s frog and toad populations, the survey involves an army of volunteers driving, stopping and listening for the amphibians calling across the state. The survey covers an average of 200 routes annually; not all routes are covered every year, with volunteers trained to record both the amounts of calling they hear as well as the different species.

Volunteers travel along an established 10- stop route, driving for a half mile, then stopping and listening for five minutes. They record what they hear on a scale from 0, hearing nothing, to 3, too noisy to count individual calls, for each species.

Lori Sargent, who coordinates the survey for the DNR’s Wildlife Division, says the survey is designed to provide a simple index to give wildlife managers an idea of which direction Michigan’s frog and toad populations are heading.

“We know that the common species, the green frog and the American toad, are fairly stable,” Sargent said. “The rare species, Blanchard’s cricket frog, Fowler’s toad and mink frog, are still pretty rare.”

Michigan boasts 12 species of frog and two species of toad. Some are widespread across the state. Others are found in specific areas. The mink frog, for instance, is found only in the Upper Peninsula. The boreal chorus frog is found only on Isle Royale.

“Bullfrogs are around and reported all over the state, but they’re not real common,” Sargent said. “Spring peepers are probably the most common; they’re certainly the loudest.

“Fowler’s toads are found only on the west shore, but I’ve had people say they’ve heard them on the east side, but that’s not confirmed,” she explained. “Blanchard’s cricket frog used to be more widespread across the southern half of the Lower Peninsula, but now we only hear them in the lower two tiers of counties. Green frogs are very common. Eastern gray tree frogs are common, too.”

Sargent said that volunteers for the survey come from a wide pool of amphibian enthusiasts.

“I’ve got teachers doing it with their classes, from elementary school to college,” she said. “There are clubs and individuals, too.”

Although frog and toad populations have been decreasing in some parts of the country, notably the West, Michigan’s populations seem to be holding up well, Sargent said. Some species, however, are in decline.

“Relative to how they once were, leopard frogs are less common than they used to be,” she said. “Pickerels, which can be confused with leopards, are even less common.”

Blanchard’s cricket frog is a state-threatened species. The boreal chorus frog is a species of concern. Sargent said she has some professional concern about Fowler’s toads, they were not reported in the 2011 survey, but the information doesn’t justify their listing as such quite yet.

Although frogs and toads are well down the list of animals most folks are interested in, Sargent said the DNR is very concerned about their well being.

“These things have been here for millions of years,” she said. “They’re pretty adaptive. But they’re kind of an indicator of environmental health, so if you see them wicking out, you know something’s going on.

“They’re important wildlife; an important food source for birds, snakes and some mammals; and they also eat their fair share of mosquitoes and other insects, that’s important, too.”

The survey “really monitors the habitat,” Sargent said. “If you see frog populations going down, you know you have a wetlands or water quality issue.”

The frog and toad survey will continue through early summer, and the results will be compiled and published. The survey is relatively inexpensive to conduct, as it’s conducted mostly by volunteers. It’s funded, in part, by the folks who buy wildlife conservation license plates. Volunteers are trained to distinguish the various calls and, although the DNR hasn’t held a training session in several years, compact discs are available for volunteers who want to study up on identifying calls.

Amphibians–as well as reptiles–are actually managed by the DNR’s Fisheries Division. Those 17 years of age and older must have a fishing license to take them. The limit is 10 amphibians of all species combined, though Blanchard’s cricket frogs and boreal tree frogs may not be taken.

That’s probably never been a concern of 10-year-old boys. But it is probably of some comfort to 10-year-old girls, who now know there are two species they are less likely to have put down the back of their blouses by those devilish little boys.


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