Combined impacts of habitat degradation and cyclones on a community of small mammals

We determined the combined impacts of habitat degradation and recurrent cyclones on a community of small mammals in a rainforest landscape in Madagascar. We used capture-release and morphometry data of 609 individuals of shrew tenrecs, rodents, and nocturnal lemurs, and vegetation surveys from 360 plots in four sites with different degradation levels for four field seasons (2021-2023) separated by two cyclone events. Combined impacts of degradation and cyclones significantly affected small mammals' diversity and capture abundance and only the body mass of the lesser tufted-tailed rat and brown mouse lemur. Diversity, capture abundance and body mass decreased immediately after the cyclones, and bounced back 4-5 months later, except in the forest fragment. We also examined the independent effects of habitat degradation using vegetation structure as it had more impacts than cyclones on small mammals. Plant diversity, canopy cover percentage, mean diameter at breast height, and estimated height significantly impacted small mammals' diversity, capture abundance, and body-mass with species-specific variations. Our results suggest that recurrent cyclones may act as an intermediate disturbance factor, while habitat degradation might have permanent impacts on small mammals, emphasizing the importance of long-term monitoring of wild populations to understand their spatiotemporal dynamics and their effective conservation.