A gecko has become the first creature in 2014 to join the impressive list of endemic species of Sri Lanka. The new species, discovered in Rammalakanda forest, has been named Rammale day gecko (Rammale diva huna), classified scientifically as Cnemaspis rammalensis.
New species: Active during the day
Unlike the common house gecko that is found hunting insects near lamps in most households at night, the new species is mostly active during the day.
Sri Lanka is home to at least 44 species of geckos including the new fellow, and most of them are active in the daytime, according to the well-known herpetologist Mendis Wickremasinghe, who led the research team that discovered the new species. The Rammale day gecko is the largest among the “daytimers” with a snout-to-vent length of 52–54mm.
The new species is a rock-dweller found only in few caves and well-shaded boulders in the Rammalkanda Forest. They were found only on rocks and not on adjacent trees. The pattern on the gecko’s body gives it camouflage in rocky habitats during the day, and the rock cavities give it protection at night.
The researchers combed similar habitats in adjacent secondary forest and well-wooded home gardens nearby, but the gecko is restricted to the Rammalkanda forest, a special Wet Zone lowland rainforest patch located in between Matara and Hambantota. Rammalakanda is the southern-most major mountain ridge in the island. It may be considered an outpost of the Rakwana massif which is well separated from other ridges of similar elevation in the area.
Researchers say the occurrence of such a large species in a small forest patch at the edge of the wet zone is unexpected.
The find highlights the importance of Rammalkanda forest which is already declared a National Man and Biosphere reserve although illegal tree-felling to cultivate tea is a major threat in the area. Tea plantations and human settlements in the surrounding areas are slowly expanding and encroaching into the forest, gradually destroying species’ habitat.
The gecko find was reported in the reputed scientific journal ZooTaxa by Dulan Ranga Widanapathiarana, Gehan Rajeev, Nethu Wickremasinghe, Samantha Suranjan and Mendis Wickremasinghe. The discovery comes from the Biodiversity Gap Analysis project conducted in collaboration with the Biodiversity Secretariat of the Ministry of Environment, funded by Nagao Natural Environment Foundation and Dilmah Conservation.
|Lanka advantaged in biodiversity year
The year 2014 has been declared International Year of Small Island Developing States by the United Nations. Along with this, the Convention of Biological Diversity (CBD) has dedicated this year to the value of “Island Biodiversity”.
Sri Lanka is already recognised as one of the biodiversity hotspot of the world. Being an island has helped as islands harbour higher concentrations of endemic species than do continents.
When animals become isolated and links with rest of the world are limited. They often evolve separately than in other areas. Scientists have found that the number and proportion of endemic species rises with increasing isolation, island size and topographic variety.
Island species are also unique in their vulnerability: of the 724 recorded animal extinctions in the last 400 years, about half were island species. Over the past century, island biodiversity has been subject to intense pressure from invasive alien species, habitat change and over-exploitation, and, increasingly, from climate change and pollution according to Convention of Biological Diversity. Unique species in Sri Lanka too increasingly face a similar threat.