Herpin' around: Thought it just took a little water to make these critters happy? Biologists say it takes trees to make frogs sing and snakes slither

American Forests, Spring, 2002 by T. Edward Nickens

On the side of the road in the middle of south-central Virginia nowhere, I cock my ears towards a patch of woods and try to make sense of an otherworldly clamor. It is inky dark, with fireflies flashing in the trees and a gibbous moon hanging over Venus.

But I can't think about stars or synchronously combusting beetle bellies. Matter of fact, I can barely hear myself think. I am covered up in amphibian acoustics, an unbelievable and ancient cacophony of singing frogs and toads. Cricket frogs click. Fowler's toads screech. Green frogs ploink like loose banjo strings. I hear a leopard frog, the sound of rubbing two wet balloons together: wreaaaak wreaaaak. Gray treefrogs trill in an unending chorus, like a herd of bleating woodpeckers.

This roadside forest is hut a scrubby mix of hardwoods and pines, with a wet smear of inch-deep creek running through the middle. But on this late spring night it is an orchestra pit. Frog and toad calls boil out of the woods, braiding together in a symphony of spring.

When most people think of amphibians and reptiles, the images in their minds are likely of wet, mucky, oozy places. Ponds and rivers. Creeks. Swamps. Desert seeps. But in years of "herping"--a curious term for that curious hobby of looking for frogs and salamanders and toads and turtles in the wet nights of spring and summer--I've discovered that some of the best places to ferret out amphibians and reptiles have as much to do with woods as water. Many of my favorite herp memories (surely you have a few?) took place in places where water was just a small component of the habitat.

One wet night in Massachusetts, I lay on my belly and watched scores of spotted salamanders migrate down a wooded hill towards a vernal pool below. A half-foot in length, the onyx-colored sallies live underground for months at a time, then emerge from subterranean chambers dug along tree roots to move downhill to breeding waters formed by melting snows and warm rains.

On another early-spring night not far from home in my native North Carolina, I hiked into a large block of woods where hurricanes had toppled trees. Untold numbers of tiny ponds had pooled in the root-wads, attracting uncountable numbers of breeding frogs. A chorus of spring peepers was so deafening it nearly drowned out the chorus frogs, whose exuberant songs nearly drowned out a lone, early-bird bullfrog.

And there by the side of that back-road, in a nondescript block of mixed pines and oaks, came a chorus beyond description. Viable woodlands are just as critical as clean waters for frogs, toads, turtles, salamanders, newts, and many species of reptiles.

AMPHIBIANS NEED TREES

That lesson is not lost on biologists seeking to restore habitat to places around the country that have lost many of their native trees. Prom the Eastern Seaboard to Arizona and beyond, projects to plant trees are becoming a boon to reptiles and amphibians.

These animals need trees for a number of reasons.

"The trouble with amphibians," explains Bill Schultz, a biologist with the U.S. Fish and Wildlife Service, "is that they can't disperse if you clear out all their habitat." In Maryland, Schultz is part of a consortium of state and federal agencies, conservation groups, and private landowners working to restore native hardwoods cloaking more than 50 miles of riparian corridor along the Chesapeake Bay and its tributaries. Farmed for many years, these streamside acres are being rented from landowners and re-established with trees.

Using Global ReLeaf funds, more than 100,000 trees--black walnut, oak, sycamore, persimmon, dogwood, and others--have been reseeded along Maryland's Chesapeake waterways. For green tree frogs, spotted turtles, and American toads, the new woods provide cover and small depressions, which fill with water just in time for breeding season.

These reclaimed areas were once heavily farmed, so the trees help absorb and break down pesticides and herbicides, which means cleaner waters. "By planting trees," Schultz says, "we're giving them another chance." And a better one.

Any time natural vegetation and cover are restored to disturbed sites, reptiles and amphibians benefit. But in places like southern Texas, specific kinds of habitat are particularly critical. Along the lower Rio Grande River, more than 90 percent of the natural brushland habitat has vanished. What natural brush remains is fragmented and isolated and is the focus of a restoration plan at the Lower Rio Grande River Valley National Wildlife Refuge.

The key in this region is to revegetate corridors between remnant stands of native trees and shrubs, such as acacias, cacti, Texas ebony, and guayacan. Officials have targeted 750 acres for revegetation each year for the next half-century.

"Perhaps the most important benefit to wildlife is our goal of providing connections to the islands of habitat that remain," says David Blankinship, a wildlife biologist with the three national wildlife refuges in south Texas.

TRAVELING AMONG THE TREES

Corridors for wildlife ensure that local populations can mix, increasing the genetic diversity of a local population. And replanting creates a place to live and a prey base to live on. Insect populations diversify when you increase vegetation, Blankinship explains, and many amphibians and reptiles depend on insects. In addition, predator species such as the Texas indigo snake need a healthy population of rodents, which in turn thrive wherever insect populations are high. The glossy blue-black snake, endangered in the state, is one of the country's largest reptiles, growing up to 8 feet long.