Spatial-Temporal Variations in Dietary Consumption of Two Dominant Rodent Species (Rhabdomys dilectus and Lophuromys acquilus) on Mount Kilimanjaro, Tanzania

Abstract

Understanding the resource partitioning and diet of sympatric species is vital for conservation and management. From April 2020 to March 2021, a study on the dietary consumption of Rhabdomys dilectus and Lophuromys acquilus was conducted on Mount Kilimanjaro. Rodent trapping was conducted in agricultural fields, fallow land, and moorland habitats during dry and wet seasons. Sherman live traps and snap traps were alternately placed in transect lines for three consecutive nights. We calculated the percentage occurrence and contribution of dietary items, niche breadth, and niche overlap of the two species across habitats and seasons. Both species consumed all the examined food items. The most abundant components were vegetative materials and seeds/starch, followed by invertebrates. R. dilectus and L. acquilus preferably consumed seeds and invertebrates, respectively, as their primary food source. Niche breadth differed significantly between species (W = 650, p = 0.002), habitat (Kruskal–Wallis chi-squared = 6.82, df = 2, p = 0.03), and season (W = 700, p = 0.000). There was a considerable niche overlap in diet (ranging from 0.84 to 0.98) between the species and was relatively higher in the dry season compared with wet season. Despite the observed niche overlap, spatial-temporal variations in dietary consumption between the two species can serve as a mechanism of resource portioning enabling their coexistence.