Drivers of amphibian diversity in disturbed wetlands of Kenya’s central highlands

Amphibians are the most threatened class of vertebrates, facing severe global declines driven largely by anthropogenic pressures such as wetland drainage. As key bioindicators, monitoring anuran populations is essential for assessing habitat degradation. Here, we examine how human activities—including noise pollution—affect water quality and habitat conditions, and how these factors influence anuran abundance, diversity, and distribution in disturbed highland wetlands in Kiambu County, Kenya. Auditory surveys and spotlight searches were conducted between June and August to monitor anurans, alongside measurements of ambient noise, water-quality parameters, and habitat classification. Diversity, abundance, and rarity were quantified using the Shannon diversity index, Pielou’s evenness, and the Index of Relative Rarity (IRR). Species–habitat associations were analysed using correspondence analysis, principal component analysis (PCA), and generalised linear models (GLMs). GIS overlay analysis was used to assess habitat preferences. We recorded 11 frog species from seven families. Species diversity was higher in the Brackenhurst and Tigoni wetlands (both H′ = 1.63) than in the degraded wetland (H′ = 1.34). The IRR indicated greater rarity in the less disturbed sites (Tigoni: 0.23; Brackenhurst: 0.18) than in the degraded site (0.08). Multiple regression identified pH and total dissolved solids (TDS) as significant predictors of diversity, explaining 72% of the observed variation. Overall, water quality emerged as a key driver of community structure, while anthropogenic noise was associated with reduced anuran diversity and abundance. These findings support the need for broader spatiotemporal monitoring to inform wetland management and amphibian conservation.