Occurrence and distribution of Herpetofauna in Mutumba Wetland, Namayingo District, Uganda

Abstract

The study investigated the diversity and distribution of herpetofauna in Mutumba wetland, Namayingo district. The overall objective of this study was to contribute herpetofaunal information that can be used to inform conservation planning and management. Data was collected for 12 days each month for a period of six months (November 2023 to March 2024). Visual encounter surveys, call count and opportunistic encounter techniques were used to accomplish the study objectives. Field surveys were performed around 40 random survey points separated by a distance of 500 meters within Mutumba wetland. Each of these survey points was surveyed 12 times to record the amphibian and reptile species. Six survey points were searched daily (day and night) for three hours per search by a team of three persons; sampling 3 points at night from 18:00 to 21:00 while another 3 points in the early morning hours from 06:00 am to 08:00 am. Data collected were analyzed using a variety of statistical methods namely: species accumulation curve, Simpson index of diversity, agglomerative cluster analysis and canonical correspondence analysis. The study documented 41 amphibian species from six families and 31 reptile species from twelve families in the Mutumba wetland. Amphibians were found across nine different microhabitats, while reptiles occupied ten. Both groups exhibited significant species diversity in cultivated land microhabitats, with Simpson’s index (D) values of 0.87 for amphibians and 0.88 for reptiles. However, amphibians exhibited greater species evenness compared to reptiles. The most abundant amphibian families were Ptychadenidae and Bufonidae with species Mascarene Grass Frog, Striped Grass Frog and African Common Toad being the most prevalent; while Scincidae dominated among reptiles. Amphibians were commoner in rice gardens and papyrus microhabitats, while reptiles were more common in tree canopy and artificial structures. Overlap in microhabitat use was observed, but environmental variables did not fully account for species distributions, suggesting other factors may be important. Species of the Hyperoliidae family, typically found in papyrus microhabitats, have become less common, possibly due to changes in the availability of these habitats from human activities. This study emphasizes the need for conservation of these habitats to ensure the sustainability of amphibian and reptile populations Future research should explore multiple environmental influences to enhance understanding of species distribution dynamics.

Keywords: Amphibians, Reptiles, Diversity, Distribution, Mutumba