Frogs of Coorg
  The Western Ghats are a chain of mountains running from Bombay to the southern tip of India. They are home to some of the most diverse frog communities on Earth. Over 90% of the species there are found nowhere else, and there is evidence that individual hilltops harbour unique species. We produced a multimedia guide to the amphibians of Coorg that includes advertisment calls and details of larval stages. Visit the Frogs of Coorg Website!>
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Visit the Frogs of Coorg Website!>
 
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Background: The Western Ghats are a chain of mountains running from Bombay to the southern tip of India. They are home to some of the most diverse frog communities on Earth. Over 90% of the species there are found nowhere else, and there is evidence that individual hilltops harbour unique species.

The Problem: It is likely that most frogs of the Western Ghats remain unknown to science. The taxonomy of amphibians in India is a neglected subject and as a result identifying species is a difficult task. The forests of the Western Ghats have been largely cleared, leaving isolated fragments of habitat and it seems inevitable that highly localised species will become extinct without ever being discovered. At present surveys of amphibians communities are rarely carried out, and often suffer from taxonomic uncertainities and methodological flaws which make comparisons of quantititve data between communities impossible.

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Rhacophorus lateralis, rediscovered in the Western Ghats after 120 years


Our Solution: Develop methods for surveying large and complex amphibian populations in an easily repeatable manner. Make amphibians easy to identify by producing guides to the frogs of the area that include pictures of animals at all stages in life, together with samples of their advertisement calls. Use these media to publicise the fact that amphibians in the area are of world-wide importance.
20th Century amphibian surveyors have relied largely on large area transects to document populations. We find these methods very ineffective because animals leave the area before they can be recorded, a large number are simply overlooked and the microhabitat is difficult to describe accurately. Quite simply it is impossible to search large areas properly. Instead we developed a method which utilises a cubic meter volume from which frogs are unable to escape, easy to find and microhabitat type can be characterised easily. This method allows large hetereogenous habitats to be sampled without bias and ensures that amphibians are not overlooked. The equipment needed is both simple and inexpensive (less than US$2).

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Dr B. Maheshwaran with the sampling device.
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As well as taking photographs of adult and juvenile frogs we raised large numbers of tadpoles and documented each stage. Being able to identify tadpoles is essential if we are ever to understand why amphibians disappear when their habitat is altered.

Previously no recordings of Indian amphibian calls were available. Calls are particularly useful in the study of the rarest members of the community, because they tend to be arboreal or cryptic species, that are usually overlooked in rapid assessments. Calls are also invaluable in determining the taxonomic status of some groups, which contain many species that look very similar, but attract mates using very different songs.

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We chose a coffee estate bordering Nagarhole National Park for this project because we wanted to sample both undisturbed and agricultural areas. Using this methodology we were able to estimate amphibian diversity, density and biomass in a wide range of habitats. The result was one of the most detailed studies of a single amphibian community ever carried out in Asia.

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Cassettes, cds and magazine articles about the frogs of Coorg have been distributed to many people in the area, particularly on coffee estates where thoughtful management can allow many frog species to survive that would otherwise be driven extinct.

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Click here for the multimedia guide to the Frogs of Coorg
 
 
 
©Daniel Bennett/Katie Hampson 1998-2002