Behavioral interactions between a coexisting rodent Micaelamys namaquensis and macroscelid Elephantulus myurus

Abstract

Abstract A number of mechanisms are known to influence coexistence in small mammal communities. However, the role of behavioral interactions in promoting species coexistence is under-represented in the literature. We studied the behavioral interactions of two coexisting small mammals, the Namaqua rock mouse Micaelamys namaquensis (Rodentia) and the Rock sengi Elephantulus myurus (Macroscelidae), which have high dietary and microhabitat overlap. Using wild-caught individuals, intra- and interspecific dyadic encounters were staged in tanks on a neutral rocky outcrop. Interspecific dyads displayed significantly more active avoidance behavior. There was no support for the prediction that the larger, more specialist species, E. myurus, is behaviorally dominant over M. namaquensis. Intraspecific encounters of E. myurus showed significantly more passive avoidance and amicable behavior, whereas the behavior of M. namaquensis did not differ between intra- and inter-specific encounters, both of which were characterized by low levels of aggression and amicability. Thus, due to the lack of aggression, direct competition appears weak and instead mutual avoidance may reduce or minimize interspecific interactions, potentially promoting coexistence.