Anurans Species Diversity and Composition along the Successional Gradient of the Evergreen Rainforest in Silago, Southern Leyte, Philippines

Abstract

Different stages of succession occupy different composition of anurans species which can be useful in determining their specific habitat requirements and preferences. The study assessed anurans species composition and diversity along a successional gradient of an evergreen rainforest in Silago Southern Leyte Philippines. A line transect (100 m) was used in the study using opportunistic approach in the collection of anurans in the established transect line per site where this was done both in daytime and nighttime. Identification of anurans was done using field guides by comparing photos collected and morphometric measurements and with final confirmation from an expert. The results showed that anuran species and diversity were considerably higher in late successional stage compared to early successional stage and grassland. There were five species of frogs (i.e Platymantis guentheri, Platymantis corrugatus, Occidozyga laevis, Platymantis sp. and Staurois sp) inhabiting the late successional stage and were not found both in early successional stage and grassland area while Hylarana erethraea (an introduced and invasive species) was documented in both early successional stage and grassland area. Furthermore, the morphometric measurements indicated that frogs found in the late successional stage were bigger compared to the same frogs found in the early successional stage and grassland. Finally, a change in species composition was observed along the successional gradient where the number of species observed in late successional stage, early successional stage and grassland were S=7, S=4, and S=2, respectively.