Within and between‐site distribution of frog species on the Udzungwa Plateau, Tanzania

Abstract

Amphibian distribution and abundance patterns are linked with environmental factors that define the suitable habitat for each species on both macro and micro scales. Determining the distribution and habitat requirements of species is a necessary first step in monitoring population persistence or declines and implementing conservation strategies to counteract global amphibian declines. Although amphibian population declines and extinctions are recorded globally, taxonomic and geographical sampling has been uneven, especially in tropical regions. With the exception of southern Africa, data on abundance and populations trends of African amphibians are severely lacking. To address this gap, we investigated community structure and microhabitat distribution of breeding and post‐breeding anuran species at Mtele Swamp, a high‐elevation wetland on the Udzungwa Plateau, Tanzania. Over a two‐week period of intensive sampling during the rainy season of 2001, we recorded species presence, microhabitat use, and distribution using visual and aural surveys and random plot sampling yielding a total of 86 individuals of 11 species of frogs. Microhabitat distribution results reveal a clear ecological stratification between species. To place our community findings in a broader context, we compared species composition at this site with similar sites in wet, montane grasslands and forest wetland sites at similar elevations in the Udzungwa Mountains. Communities show little species overlap between these sites, even between geographically close and elevationally equivalent sites. The most similar community to the study site was miombo woodland of low elevation in central Kenya, not the much closer and more elevationally equivalent Udzungwa Mountain sites. Differences probably reflect a closer affinity between habitats (miombo woodland vs. forest) than elevation. This study provides baseline information for monitoring the anuran community at Mtele over time for changes in numbers, species composition and diversity that may be indicative of population declines.