Among all life on earth, amphibians are unique in representing a bridge between aquatic and terrestrial organisms. The word amphibian itself is from the ancient Greek for “two lives.”
The current thinking in biology is that amphibians were among the first animals to leave the water and live on land. However, all amphibians are tied to water for life, as they must return to aquatic (or at least wet) environments to reproduce.
Amphibians have been around for nearly 400 million years with around 7,000 species found throughout the world today, most of which are frogs and toads.
In Maryland, one of the first sure signs of the end of Winter and the start of Spring is a shrill (and sometimes deafening) chorus of spring peepers mixed with hoarsely quacking wood frogs, beginning in late March. The chorus then continues around ponds, pools, wetlands, and marshes—as leopard frogs, tree frogs, toads, green frogs, and finally bullfrogs make their presence known and call for mates and territory.
As a child, I remember spending many days chasing the calls of amphibians—catching adult frogs and toads, looking for tadpoles, and even encountering the occasional spotted salamander under just the right log. Many of the students that come to Marshy Point on school field trips, and some of the children that visit with their families, also pursue these interesting creatures.
Amphibians also fill important ecological roles as both predator and prey, and as an environmental indicator species. That is, amphibians are especially sensitive to changes in the environment and the presence of disease, pollutants, and toxins. They have been compared to the proverbial miner’s “canary in the coal mine.” Unfortunately, these slimy amphibian “canaries” appear not to be giving us good news.
Declines in amphibian populations were first noted in the 1980s with almost half of all species in decline. The reasons seem to include habitat loss, habitat fragmentation, disease, invasive species, increased ultraviolet radiation, and pesticide use.
I find it truly disheartening that the wetlands could be rendered silent in Spring as amphibians disappear. If amphibians are the ecological “canary in the coal mine” that they seem to be, why aren’t we listening? The same world that supports amphibians supports humans and all other life. If amphibians are in trouble, it likely means that trouble for humans and the rest of Earth’s species is not far away.
We must recognize this fact: Saving the amphibians is a first step toward saving ourselves as well. Good places to start include protecting existing habitat and promoting habitat restoration, working to control the spread of non-native species, and supporting amphibian conservation and research efforts.