Elephant Rewilding Indirectly Affects Rodent Site-Use and Behavior by Moderating Coarse Woody Debris Density

Megaherbivores such as African savannah elephants (Loxodonta africana) are key ecosystem engineers that modify vegetation structure through processes including tree felling and branch breakage. However, the cascading effects of these structural changes on smaller fauna remain poorly understood. Here, we examined how elephant rewilding influences coarse woody debris (CWD) density and, in turn, the behavior of a common rodent, the Natal multimammate mouse (Mastomys natalensis), in lowveld savannah, South Africa. Using field surveys and manipulative experiments, we quantified (i) CWD abundance across reserves where elephants had and had not been restored (henceforth "rewilded") by 2003, and (ii) rodent site visitation, behavior, and giving-up density (GUD) within CWD and adjacent open microhabitats. Bayesian models showed that medium- and large-sized CWD density was on average 5.5 and 18.0 times higher where elephants had been restored than not. Rodent visitation, feeding, and resting behaviors were on average 1.66, 1.76, and 7.75 times higher in CWD than open areas, while GUD values were on average 1.1 times higher in open than CWD areas, indicating reduced perceived predation risk in CWD. These findings suggest that elephant-induced habitat modifications create structural refugia that influence rodent foraging and risk perception, consistent with the "landscape of fear" framework. By altering fine-scale habitat heterogeneity, elephants indirectly influence small-mammal behavior, which is likely to affect processes such as seed predation and secondary dispersal. Our results provide evidence that megafauna rewilding can reinstate lost trophic interactions and behaviorally mediated ecosystem functions, emphasizing the importance of considering cross-trophic behavioral pathways when evaluating restoration outcomes.