Frogs croak out warning

Loss of lakeshore habitat may signal problems for North Woods

Monday, March 03, 2003
Web posted at 12:00:01 AM EST

Susanne Quick
Milwaukee Journal Sentinel

(MILWAUKEE, WISCONSIN, USA) Although people and construction have been flooding into northern Wisconsin like a biblical plague of frogs, hardly a ribbit has been made from the resident green frog population.

The accelerated lakeshore development occurring in counties such as Oneida and Vilas is interfering with green frog habitat, according to a study released in the April issue of Biological Conservation.

"And these frogs aren't your little rare, sensitive frogs," said Jim Woodford, a researcher for the Wisconsin Department of Natural Resources and co-author of the study.

Green frogs are abundant and hardy.

They are like the mosquitoes of amphibians, said Woodford. "Where you find standing water, you find green frogs."

But according to the study, the habitat of these green frogs is quickly disappearing.

Since the early 1960s, nearly 60% of previously undeveloped lakes larger than 10 acres have been developed. According to a DNR report, in 20 years the remaining lakes of this size will all be developed.

Making the public aware of the possible side effects of lakeshore development, especially with the perks of looking through one's window every day at a northern Wisconsin lake, is going to be difficult, said Michael Meyer, an environmental toxicologist and researcher at the DNR and co-author of the study.

"It's hard to get people excited about green frogs," he said. "But that's really not the point."

The point is, he said, the long-term effects that lakeshore development will have on the native wildlife populations of northern Wisconsin.

"These frogs are just a sign of things to come."

During summer 1997, Meyer and Woodford patrolled the borders of 24 northern Wisconsin lakes in canoes. Twelve of their study lakes, including Jag and Frank lakes in Vilas County, had little or no development; the other 12 had a lot. For lakes like Heiress and Virgin in Oneida County, more than 50% of their lakeshores have been altered.

What they discovered, listening and recording green frogs' chirps, was that on those lakes with few or no lakeshore homes, a cacophony of chorusing croakers was heard.

While on lakes with lots of turf grass and few trees along the shore, green frog peeps were fewer.

"They do have a nice sound," said Meyer, describing the banjo-esque twang of the male green frog's chirrup. "And if you get a lot of them going at once, it can be almost deafening."

The problem with lakeshore development, said Meyer, isn't so much the fact that there are houses around a lake. It's what is done to the immediate lakeshore environment.

Green frogs hang out and breed in low-lying shrubs and dense, high grasses that surround lakes. But on many of these lakes where houses are being built or remodeled, that vegetation is pulled and replaced with turf grass, cement walls and manicured lawns.

Although the state and individual counties have laws requiring that homeowners leave almost two-thirds of their shoreline property intact and wild, the language is vague and loopholes are easy to find, Meyer said.

"So they raze everything, except that one tree," and contend that they have maintained suitable habitat, he said.

According to Glenn Schiffman, a builder and developer from Eagle River and a representative on the state's Natural Resources Board, the problem isn't new development.

New developments are required to meet minimum state and county requirements, such as being set back 35 feet from the shore and leaving habitats partially intact.

"They say that lakeshore development is going to hurt animal populations," Schiffman said. "But how can you say that something is going to happen when it hasn't happened?"

The science is suspect, he said, alluding to the fact that this analysis took place over only one field season.

Woodford said that this may diminish the power of the study. "It could have been a weird year," he said, adding that to make the study really convincing, the data collection should have occurred over several years.

But other studies, conducted by Meyer and the DNR, have shown similar effects of lakeshore development on birds, vegetation and fish. The plight of the frogs adds further documentation of the deleterious side effects of lakeshore development on native wildlife, Woodford and Meyer say.

In response to these studies by Meyer and others, the DNR and the state are considering new zoning regulations.

Proposals include extending the 35-foot buffer between the lake and new development, classifying lakes based on their sensitivity to pollutants, and reconsidering clear-cutting parameters.

Although some counties, like Vilas, have mandated some of these stricter regulations on their own, the DNR would like to see these standards applied statewide.

"We are looking to strike a balance between keeping the environment intact and letting people use and enjoy the natural beauty" of northern Wisconsin's lakes, said Scott Watson, DNR central sub-team leader.

"Science makes us smarter about these things," he said. The results of studies like the green frog survey point to trends that need to be considered.

Schiffman believes the laws already in place are adequate.

"Don't fix what's not broken," he said.

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Reprinted from http://www.frogs.org/news/article.asp?CategoryID=10&InfoResourceID=1775