Elephants change savanna vegetation and at high densities reduce shrub and tree cover. The absence of elephants alternatively prompts increases in cover. Southern African savannas shift toward grass-dominated systems or shrub-dominated habitats, which impact rodent communities. As rodents are critical components of savannas, we sought to understand how and why they respond to different vegetation types. Using sites in Kruger Park (elephant presence) and in Swaziland reserves (elephant absence), we assessed how vegetation across a cover gradient shapes rodent communities. Kruger sites were open with limited woody cover, high grass, and low rodent diversity. Swaziland sites had higher cover levels, lower grass levels, and higher diversity. On average the community responded positively to both grass and woody cover, while individual species showed varied responses. Kruger’s common species, Mastomys natalensis, responded positively to grass but negatively to shrub cover, matching Kruger’s vegetation.
We then tested whether fear of predation explains some species’ decline in open grasslands. Loss of cover may increase perceived risks for rodents, shifting them towards “safer” covered habitats. We estimated rodent risk perceptions using Giving-up Density feeding trays placed across the cover gradient: inside a shrub, at the shrub’s edge, and 3m away from shrubs. Rodents consumed more seeds under shrubs than further from shrub cover, suggesting that they perceive open areas as risky. Using camera traps, we monitored each species’ foraging behavior and activity patterns. Most species primarily foraged under shrubs. M. natalensis foraged in all trays, appearing to thrive in open landscapes without fear.