Frogs - Discovery and Extinction in Sri Lanka


New species of amphibians are being discovered at a remarkably rapid rate. AmphibiaWeb reports that during the past eight years 1336 new species of amphibians were described, that is one new amphibian species every 2.18 days for 8 years. We are only about 37 days into 2011 and 14 new species of amphibians have already been described (about one species every 2.7 days). In January 2010, an article in New Scientist reported the discovery of 30 new frog species in western Ecuador, 14 of which were found in a patch of cloud forest only a couple of miles wide. Needless to say most of the newly discovered amphibians are frogs, but the occasional new salamander or caecilian are found. 
Caption: The Sri Lankan Bush Frog, Pseudophilautus schmarda (Kelaart, 1854) is known only from the forested hill area of central Sri Lanka between 800 and  2300 feet above sea level. It can be found in low  vegetation and on the ground. JCM Natural History Photography.



However, despite the fact that new species are being discovered at a rapid rate, signs that amphibian species are disappearing due to human modifications of the environment are prevalent. Tthe Wildlife Heritage Trust of Sri Lanka conducted extensive surveys of the island’s amphibian fauna between 1993 and 2003 and discovered a large number of new species. An examination of the Natural History Museum (NHM- London) collection revealed about 140 specimens of frogs collected in Sri Lanka between 1850 and 1940. This was a time when rainforests were being cleared for tree planatations in the island's central mountains and southwestern wet zone. The wet forested habitat was reduced from about 16,000 km2 to about 750 km2. The NHM collection included 19 species of frogs (now placed in the genus Pseudophilautus) that have yet to be found on the island and are presumably extinct. Of particular interest was a frog Meegaskumbura et al. (2007) named Philautus maia (now Pseudophilautus maia), which appears to have carried its eggs attached to the abdomen, a behavior unknown in any other frogs. It has not been seen since 1876.


Now, Meegaskumbura and Aanamendra-Arachchi (2011) have described two, very small, new species of Sri Lankan shrub frogs in the genus Pseudophilautus. Pseudophilautus schneideri and Pseudophilautus hankeni, (22.8 mm and  21.9 mm SVL respectively). Pseudophilautus schneideri inhabits shrubs in open areas of the low to mid-elevations of the island’s southwestern wet zone that receive about 2 m per year, while P. hankeni  occurs on shrubs in the understorey of montane forests of the highest peaks ( 1,200–1,600 m elevation) of the Knuckles region. These two new frogs raise the total number of valid species of Sri Lankan Pseudophilautus to 67, 48 of which are extant and 19 are believed to extinct.  

Literature
Meegaskumbura, M. and K. Manamendra-Arachchi. 2011. Two new species of shrub frogs Rhacophoridae: Pseudophilautus) from Sri Lanka. Zootaxa 2747:1-18.
Meegaskumbura, M., K. Manamendra-Arachchi, C. J. Schneider, and  R. Pethiyagoda.  2007. New species amongst Sri Lanka’s extinct shrub frogs. Zootaxa, 1397, 1–15.

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