ECONNECTION
Amphibians
by Karen Dusek

This month's column is the first of a two-part series on amphibians.

My mother and I were out walking in the woods one spring day when we heard a tremendous racket that sounded like a huge flock of ducks all quacking at once. Curious, we left the trail and made our way to a small pond barely visible through the undergrowth. As we got closer, however, the noise stopped abruptly, as though someone had pulled the plug on a boom box. We continued to the edge of the pond, expecting to see at least a hundred ducks floating on its surface. Instead, we saw…nothing. The pond was completely, eerily still.

Later, I learned that the raucous quacking was made not by ducks but by wood frogs, a species of frog common in the northern regions of North America and the only North American frog that lives north of the Arctic Circle. When I moved onto the farm, where I lived for the next 12 years and which was blessed with abundant wetlands, the quacking of wood frogs became a familiar and welcome sound that signaled the end of winter.

Wood frogs are one of the species of amphibians (frogs, toads, newts and salamanders) that depend on vernal pools for their survival. Also known as ephemeral wetlands or temporary or seasonal ponds, vernal pools are depressions in the earth that hold water for a period of time sufficient for breeding, egg laying, hatching and development of the various species that use them for that purpose, including some amphibians, crustaceans and insects (the species vary from one region to another). Vernal pools are a particularly appealing breeding ground for those species since the pools dry up, either annually or during drought years, making it impossible for fish that might feed on their eggs and young to live there. Sometimes as small as a mud puddle or tire track and isolated from other bodies of water, vernal pools are often plowed over by farmers, filled in for development or transformed into storm water detention ponds or permanent ponds for raising fish.

The upland area around vernal pools also continues to be developed. Because the amphibians that utilize such pools for breeding spend much of their adult lives on dry land, protection of the upland areas is critical to their survival. Acid rain, water pollution, pesticide run-off, automobiles and off-road vehicles, as well as natural predators, are other hazards that these, and other, amphibians face as they migrate from upland to breeding grounds and back. (Some, such as the leopard frog, travel a mile or more to reach their destination.)

Michigan is home to two species of "true" toad - the American toad and Fowler's toad - and 11 frog species, ranging from the hefty bullfrog to the diminutive Blanchard's cricket frog. Some, like the bullfrog, breed in permanent ponds, rather than vernal pools. Concern over the decline of wetlands and wetland-dependent species led to the initiation of the Michigan Frog and Toad Survey by the Department of Natural Resources in 1988. Survey routes consisting of 10 sites each were established and are visited three times a year by volunteers, who identify and estimate the population of the species that are present by their breeding calls or songs. The numbers are indicative of the health not only of the various species, but also of their habitat. Because amphibians absorb water and breathe through their skin, they are particularly sensitive to pollutants.

"Why should I spend my time worrying about something as insignificant as a frog or toad?" you may ask. "What have they ever done for me?"

Well, consider this. One tiny inch-long cricket frog eats about 4,800 insects every year. Ten tiny cricket frogs - 48,000 insects. One thousand cricket frogs - 4.8 million insects. The bigger the frog, the more insects it eats. You get the picture. Toads do the same, which is why any gardener worth her salt encourages them to stay by providing hiding places and shallow pans of water. Toads and frogs are also an important source of food for other wildlife species, such as herons, egrets, snakes, raccoons and humans, who capture frogs by the truckload for restaurants (and school science labs).

Also consider that all land vertebrates - birds, mammals and reptiles - evolved from amphibians (fossils of toads and frogs date back 150 million years). Consider, too, the unique metamorphosis they go through to enable them to live in water and on land. It is important to look beyond a toad's warts and secretions (when a predator attempts to eat a true toad, the toad will secrete a poisonous substance that irritates the mucous membranes and may cause nausea and even death) and a frog's slimy, mucous-coated skin (necessary to help it breathe) to its importance in the web of life. We should be revering frogs and toads, not repudiating them.

Some cultures show their respect for toads and frogs by making them the subject of myths and legends. According to Laura C. Martin in her book Wildlife Folklore, the Egyptian frog goddess Hequat "had power over the water and was considered protectress of mothers and newborn babies." Polynesians regarded toads as "symbols of death," but for Mexicans they "represented the earth." There are also several superstitions involving frogs and toads. In one, seeing a frog before a card game meant you would have good luck and in another, if a newly married couple saw a toad in the road their marriage would be happy. Frogs, both dead and alive, were also used as a cure for diseases such as thrush (the patient had to hold the live frog in his mouth) and whooping cough (frog soup).

If you've never looked for frog eggs in a pond on a warm spring day or watched tadpoles metamorphose into toads; if you've never laughed at a bullfrog's throaty call or stopped to listen to spring peepers on a warm spring evening; if you've never said thank you to a toad hunting for insects in your garden, you are missing out and, chances are, so are your children.

To encourage amphibians in your yard, you can do something as simple as leaving some leaf litter on the ground and planting native grasses, wildflowers and ground cover or building a burrow (lay a clay flower pot in a sheltered spot and bury it halfway in the earth. Put some dead leaves in the bottom or, poke a hole in the rim of a flower pot and invert it end up on the ground) to constructing a vernal pool (go to
www.fs.fed.us/r8/boone/documents/resources/vernal.pdf for complete downloadable instructions). You can also put up a light in your garden no higher than three feet off the ground to attract insects that will, in turn, attract toads. Teaching your children not to catch and keep amphibians and finding organic alternatives to lawn and garden pesticides are other proactive steps you can take to help amphibian populations.

If you do not have a lawn or garden, you can still help amphibians by supporting organizations that are working to protect them, participating in monitoring projects and promoting land use planning in your community that provides protection for wetlands, including vernal pools, and their uplands.

For more information, visit the following Web sites:

• www.epa.go/R5water/ephemeralwetlands
• www.state.ma.us/dfwele/dfw/dfwnhes.htm
• www.vernalpool.org
• www.herpcenter.ipfw.edu

For further information and ideas for activities related to tropisms, visit the Kids Gardening website at www.kidsgardening.com or do a general search under tropisms.

You may email Karen at karen@lakeshoreguardian.com.