We hear the stories. We feel the silence. Something is happening to the amphibians that used inhabit our window-wells and startle us as they leapt from our path. Amphibian populations are declining throughout the world, and we're not sure why. Like a canary in a coal mine, indicator species are used to assess environmental quality.
Amphibians have moist, permeable skins that readily absorb chemicals from the environment.
They act like sponges for toxins and pollutants. Frequently these substances, even in minute concentrations, have deleterious effects on reproduction. Some scientists believe that the decline in amphibian populations and a twenty-year decline in human sperm counts may have a common cause. Frog populations are easy to monitor. Every spring, volunteers traverse the roads of Wisconsin, visiting ponds and counting the numbers of singing frogs.