RESEARCH ARTICLE

MORPHOMETRY AND POPULATION DYNAMICS OF KIRTISINGHE’S ROCK FROG IN PITAWALA PATANA, KNUCKLES

Abstract

The Critically endangered Kirtisinghe’s Rock frog (Nannophrys marmorata) belonging to an endemic genus, is a restricted range species confined to areas within the Knuckles mountain range. Although some basic facts on its ecology have been reported previously, information on morphometry and population dynamics is scanty. The present study was conducted in Pitawala patana, within the Knuckles Conservation Forest, over a period of one year, to record population fluctuations and details of morphometry. Nocturnal searches between 1830 – 2200 h were conducted to enumerate the frogs while tadpole and egg searches were conducted throughout the year. Observations revealed considerable seasonal fluctuation in the number of frogs foraging on rock surfaces at night, suggesting marked population declines in the peak dry season. The frogs breed with the onset of the rains resulting in a gradual increase in the numbers reaching a peak in February when both adults and juveniles were recorded. Thereafter, the numbers progressively declined. No increase in frogs was noted with inter-monsoonal rains. The mean tadpole density on wet rock surfaces was 6.8 individuals per m2 in December. The sex-ratios of the randomly sampled frogs indicated a male bias in both the wet and dry seasons. The present study is the first to document population sizes of this Critically Endangered rock frog and quantitatively assess its annual population trend. With the predicted adverse effects of climate change, which will be more severe in seasonal montane areas such as in the Knuckles mountain range, ensuring the survival of this species would necessitate more stringent conservation actions in sites where populations exist.

Keywords: Rock Frogs, seasonality, population size, morphometry

How to Cite: Senanayake,U.I,Weerakoon,D.K,Wijesinghe,M.R, (2018). MORPHOMETRY AND POPULATION DYNAMICS OF KIRTISINGHE’S ROCK FROG IN PITAWALA PATANA, KNUCKLES.WILDLANKA, 6(1):Pages 015-023

Published On:2018-03-31

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