Diversity and Distribution of Herpetofauna in Ghandruk Region of Annapurna Conservation Area, Nepal

Abstract

Amphibians and reptiles share many physiological, behavioral and ecological similarities so they are kept under same group Herpetofauna. Herpetofauna are least studied group of animals in Nepal. Herpetofaunal study was performed on Ghandruk region of Annapurna Conservation Area to explore Species composition and abundance, their seasonal variation, distribution pattern along elevational gradient and habitat type. Relation of herpetofauna with multiple factors like distance to water resources, distance to road, distance to settlement, leaf litter coverage, canopy cover, shrub cover, Habitat type and elevation was also examined during the study. Diurnal and nocturnal distance and time constrain Visual encounter survey was applied on randomly selected 11 transects. Opportunistic survey was also adopted to increase the survey efficacy. Survey was performed on May for pre monsoon and October for post monsoon season. One way ANOVA, t- test, linear regression, generalized linear model, Variation partitioning analyses were performed to obtain the result. Ghandruk lies in the southern part of ACA which has an area of about 21412.977 Sq. Km. Six hundred and sixty two individuals of herpetofauna belonging to 12 species of amphibian and 13 species of reptile were recorded during this study. Amphibian diversity was significantly affected by explanatory variables like distance to water, distance to settlement and Leaf litter cover. In case of reptiles their diversity was significantly affected by Leaf litter cover, Distance of water, Distance of Settelment and canopy cover. Explanatory factors like Elevation, Habitat character, Disturbance and water distance together contribute three percent, nine percent, forty percent and thirty five percent on species richness of herpetofauna. Though diversity of herpetofauna was slightly higher in post monsoon (H'=2.26) than pre monsoon (H'=2.19) there was no any significant difference in species richness (P value = 0.220) and abundance (P value = 0.478) in between these two season. There was a declining trend in species richness and abundance with increase in altitude but their linear relationship was not significant. Herpetofauna was not uniformly distributed among different habitat type, there was significant difference (F=3.42, P<0.01) in species richness of herpetofauna in different habitat types during this study.