Extinction threat

Print edition : April 05, 2013

A six-centimetre-long 'Ctenotus ora', or the coastal plains skink. Scientists announced on October 29, 2012, the discovery of the new species of lizard 'Ctenotus ora', fighting to survive among the sand dunes outside Perth in Western Australia. Photo: BRAD MARYAN/AFP/AUSTRALIAN NATIONAL UNIVERSITY

Elegant gigotea, also known as Florida tortoises or red-eared turtles, are seen in a pound at the Museum of Archaeology in Mexico City in August 2010. It is a semi-aquatic turtle subspecies belonging to the family Emydidae. Photo: LUIS ACOSTA/AFP

One in every five reptiles is threatened with extinction, and freshwater turtles are at particularly high risk.

NINETEEN per cent of the world’s reptiles are estimated to be threatened with extinction, says a paper jointly published in the journal Biological Conservation by the International Union for the Conservation of Nature (IUCN) Species Survival Commission and the Zoological Society of London. Out of these reptiles, 12 per cent are classified as critically endangered, 41 per cent endangered and 47 per cent vulnerable.

Though the threat of extinction is not evenly spread throughout this highly diverse group, freshwater turtles are at particularly high risk because their natural habitat is under siege. The study estimated that 30 per cent of freshwater reptiles are to be close to extinction, a figure which rises to 50 per cent when freshwater turtles alone are considered, as they are also affected by national and international trade.

Although the threat remains lower in terrestrial reptiles, the often restricted ranges, specific biological and environmental requirements, and low mobility make them particularly susceptible to human pressures. In Haiti, for instance, six of the nine species of Anolis lizard included in the study have an elevated risk of extinction owing to extensive deforestation. Some, such as a jungle runner lizard called Ameiva vittata, are listed as critically endangered and even possibly extinct. Two recent searches for the species have been unsuccessful.

An IUCN press briefing quoted Philip Bowles, Coordinator of the Snake and Lizard Red List Authority of the IUCN Species Survival Commission, as saying, “This is a very important step towards assessing the conservation status of reptiles globally. The findings sound alarm bells about the state of these species and the growing threats that they face. Tackling the identified threats, which include habitat loss and over-harvesting, is a key conservation priority in order to reverse the declines in these reptiles.”

The snake and lizard list was compiled by more than 200 world renowned experts who assessed the extinction risk of 1,500 randomly selected reptiles from across the globe.

On a related note, there has been a change in the IUCN Red List assessment process. This is expected to expedite the time taken to complete a Red List assessment. The IUCN states that the new rules will not affect the rigours of the assessment process.