DIVERSITY, ABUNDANCE, DISTRIBUTION, AND CONCORDANCE OF ANURAN SPECIES IN KINGWAL SWAMP AND NORTH NANDI FOREST RESERVE, KENYA

Abstract

Anuran species are one of the good environmental indicators of habitat quality in ecosystems due to their amphibious life modes and sensitivity to environmental change caused by a rapid expansion of anthropogenic activities and climate change. Therefore, understanding their biodiversity and distribution patterns is crucial for the development and implementation of conservation strategies. The study aimed at assessing and comparing diversity, abundance, distribution, and concordance of anurans between a protected (North Nandi Forest Reserve) and a non-protected area (Kingwal swamp), which are among the underexplored areas in Kenya. Data was gathered both in the dry and wet season between October 2022 and June 2023 by employing standard sampling techniques for anurans (Visual encounter and pitfall traps with a drift fence). Three habitat types- farmland, intermediate, and forest were surveyed. A total of 1649 individuals from 21 different anuran species, belonging to nine genera and nine families were recorded. Ptychadenidae was the most abundant family from the recorded anurans, while Dicroglossidae, Arthroleptidae, Pyxicephalidae, and Ranidae were the least. Most species were found in the forest habitat (Protected), and least in the farmland (non-protected). The wet season had high species abundance, diversity, and richness compared to the dry season in all the habitats. Forest habitat had the highest values for Shannon diversity (H'= 2.432), and least in farmland habitat (H'= 2.048), even though species were evenly distributed. There was a significant difference (p < 0.05) in diversity between the habitats in the wet season, but no significant difference during dry season (p > 0.05) except for forest and farmland (p = 0.014). There was a significant difference in species abundance between seasons (p = 0.001), and between habitats (p = 0.001) in all seasons except for farmland and intermediate (p = 0.826), as well as farmland and forest (p = 0.051) during the wet season. Habitat type (p = 0.223) and season (p = 0.157) had no influence on anuran species richness. Most of the species encountered favored insects and frogs in their diet, occupied terrestrial and aquatic microhabitats, specifically stagnant water, and were predominately ground/wet terrestrial dwellers. The modest sampling indicates that Kingwal Swamp and North Nandi Forest Reserve are rich and support anuran species. However, the differences in anuran biodiversity and distribution in the 3-habitats demonstrate that conservation efforts continue to be a priority. Therefore, Nature-based organizations are recommended to engage communities along Kingwal Swamp and transform the wetland into a conserved protected area for the survival of anurans.