For frogs, spring is a raucous affair of warm evenings. In these heady nights, the quiet of winter is ruptured by peeps, croaks, rattles, honks and cackles. An innocent evening walk was always on the wild side. Alas, amphibian orgies are becoming more and more rare. Rachel Carson's bleak prophesy of a silent spring is coming true as frogs all over the World disappear leaving us only memories of loud spring assignations.
What's happening? Where have all the frogs gone?
Although nobody thinks that global demise of frogs and toads is caused by one factor, there do seem to be a limited number of possibilities. Some of these causes are reviewed in two books we published at UC Press – Amphibian Declines edited by Michael Lannoo and Malformed Frogs authored by the same Michael Lannoo. Pesticides, fertilizers and other agricultural chemicals bear some of the blame. Such pollutants find their ways into streams, creeks, rivers, puddles, ponds and lakes. Reproducing frogs, their eggs, and their tadpoles exposed to contaminates can grow into monstrosities with extra misplaced or missing limbs. Frogs and toads can be exposed to introduced or emergent diseases or parasites that kill or render infertile. Changes in lifetime exposures to certain kinds of natural ultraviolet radiation can harm eggs and tadpoles. Habitat changes due to possible climate changes have left some frogs without suitable places to live and reproduce.
Why should we care? What does the disappearance of frogs presage about the environment that we all share?
Amphibians such as frogs and toads, represent living organisms that can reveal the health of both terrestrial and aquatic ecosystems. As adults, frogs and toads live in or near water as well as in diverse terrestrial soils – the same soils in which we grow our vegetables and let our children play. As eggs, embryos, larvae and tadpoles they live in water – the same water we drink and use to irrigate our fields and wash our cloths. Amphibians live in intimate association with the environment, which is precisely why they provide such an alarming harbinger of our own future. If frogs and toads are disappearing, how long before other animals including humans are victims of our carelessness and ignorant decisions about the resilience of the environment?
Frogs may help us look into our own future. Frogs and toads, in full voice, luring mates into aquatic bedrooms for nights of reproduction may be the best signs of a healthy Earth. The approaching silence of spring without frogs may be a warning. Spring will be quiet … too quiet.
By: Chuck Crumly, Science Editor, UC Press
If you would like more information on the declining population of frogs, please visit our book pages for: Amphibian Declines: The Conservation Status of United States Species and Malformed Frogs: The Collapse of Aquatic Ecosystems.
Also, be sure to tune in to your local PBS this Sunday, April 5th, for the documentary, "Frogs: The Thin Green Line." For more information on the film, please visit the Argo Films website. A flier for the film is attached below.