Amphibians going extinct in SL at a record pace

by Ifham Nizam

Sri Lanka holds the record for nearly 14 per cent of the amphibian extinctions in the world. In other words, of the 130 amphibian extinctions known to have occurred across the globe, 18 extinctions (14 per cent) have occurred in Sri Lanka, says Dr. Anslem de Silva, widely regarded as the father of Herpetology in the country. Speaking to The Sunday Island, the authors of a news book on amphibians, said that this is one of the highest number of amphibian extinctions known from a single country. Some consider this unusual extinction rate to be largely the result of the loss of nearly 70 per cent of the island’s forest cover. Dr. Anslem de Silva, Co-Chairman, Amphibian Specialist Group, International Union for the Conservation of Nature/Species Survival Commission (IUCN/SSC), together with two academics, Dr. Kanishka Ukuwela, Senior Lecture at Rajarata University, Mihintale who is also associated with IUCN/SSC and Dr. Dillan Chaturanga, Lecture at Ruhuna University, Matara had authored this most comprehensive book on amphibians running to nearly 250 pages released last week. The prevalent levels of application of agrochemicals up to few months back, especially in rice fields, and vegetable and tea plantations, have increased over the past three decades. Similarly, the release of untreated industrial wastewater to natural water bodies has intensified. As a consequence, many streams and canals have become highly polluted, they say. The use of pesticides directly decreases the insect population, an important source of food for amphibians. Furthermore, these pollutants can easily make the water in paddy fields and the insects on which the amphibians feed toxic or increase the nitrogen content of the water. The highly permeable skins of amphibians would certainly cause them to be directly affected by these, they add. Amphibian mortality due to road traffic is a widespread problem globally that has been known to be responsible for population reductions and even local extinction in certaininstances. In Sri Lanka, amphibian mortalities due to road traffic are highly prevalent on roads that serve paddy fields, wetlands and forests. Further, they are especially intensified on rainy days when amphibian activity is high, the book explains. Recent studies indicate that amphibian road kills are exacerbated in certain national parks in the country due to increased visitation. According to recent estimates, several thousand amphibians are killed annually due to road traffic.

Professor W. A. Priyanka, PhD (USA), Professor in Zoology, Faculty of Science, University of Peradeniya says the need for a guide to the amphibian fauna of Sri Lanka is obvious, given the currently critical conditions endangering them. Amphibians are an attractive group of animals whose diversity has always sparked interest among the scientific community, creating a vast body of unanswered questions.However, the identification of amphibians has been a challenge due to the lack of a complete and informative guide. The comprehensive pictorial guide provided by the new book should thus be of great benefit to a better understanding of the unique and intriguing nature of these fascinating living beings.The authors have done an outstanding job in compiling this book. An introduction to the guide briefly describes the history, current status, threats and conservation information, along with interesting folklore associated with amphibians. With the clear and informative images, distribution maps and updated status of each species, this guide can easily be comprehended by experts and beginners in the field alike.”I firmly believe that this book will be very useful to undergraduate and postgraduate students in the fields of zoology, biology and environmental science, as well as researchers, wildlife managers and visitors,” Professor Priyanka added.The authors said that like their previous guide to the reptiles of Sri Lanka, A Naturalist’s Guide to the Reptiles of Sri Lanka (de Silva & Ukuwela, 2017, 2020), this book is intended for both naturalists and visitors to Sri Lanka, providing an introduction to the amphibians found here. It features all the extant species of amphibian in this country with colour photographs and quick and easy tips for identification. At the time of writing, 120 species have been recorded within the country and ongoing taxonomic work is certain to add more to this impressive list in the next few years.This guide provides a general introduction to the amphibians of Sri Lanka, a profile of the physiographic, climatic, and vegetation features of the island, key characteristics that can be used in the identification of amphibians and descriptions of each extant amphibian species.Additionally, it presents information on amphibian conservation here and a brief introduction to folklore and traditional treatment methods for combating poisoning due to amphibians in this country. The species descriptions are arranged under their higher taxonomic groups(orders and families), and further grouped in their respective genera.The descriptions are organized in alphabetical order by their scientific names. Every species covered is accompanied by one or more colour photograph of the animal. Each account includes the vernacular name in English, the current scientific name, the vernacular name in Sinhala, a brief history of the species, a description with identification features, and details of habitat, habits and distribution (both here and outside the country).Key external identification features of the species, such as body form, skin texture and coloration, are provided, to help in the quick identification of an animal in the field.It must be noted that according to Sri Lanka’s wildlife laws, amphibians cannot be captured or removed from their natural habitats without official permits, which must be obtained in advance from the Department of Wildlife Conservation.Sri Lanka is home to an exceptional diversity of amphibians. Currently, the island nation boasts of 112 species of amphibians of which 98 are restricted to the country. However, nearly 60 per cent of this magnificent diversity is threatened with extinction. To make matters worse, very little attention is paid by the conservation authorities or the public. The last treatise on the subject was published 15 years ago. However, many changes have taken place since then and hence an updated compilation was a major necessity. This book by the three authors intends to popularize the study of amphibians by the general public by filling this large void. Historical aspects

Sri Lanka is one of the few countries in the world where conservation and protection of its fauna and flora has been practiced since pre-Christian times. There is much archaeological, historical and literary evidence to show that from ancient times amphibians have attracted the attention of the people of this island.

This is evident by the discovery of an ancient bronze cast of a frog (see photo) discovered during excavations conducted by the Department of Archaeology and the Central Cultural Fund. Strati-graphic evidence from the excavation sites indicate that these objects belong to the sixth to eighth centuries AD (Anuradhapura and Jetavanārāma museum records). Beliefs that feature the ‘good’ qualities of frogs and association with nature. These beliefs have some positive effects on the conservation of amphibians, perhaps one reason that Sri Lanka harbours a diverse assemblage of frogs. Absence of frogs and toads in agricultural fields indicates impending crop failure, it is believed.

The authors have specially thanked Managing Director John Beaufoy of John Beaufoy Publishing Ltd, for publishing many books promoting Sri Lanka diversity.