Abstract:
Temporal separation in diel activity between species can be caused either by different realized
niches or by competition avoidance. Morphologically similar species tend to have similar ecological
niches. Therefore, morphological similarities among sympatric species may be related to
both overlap in diel activity and possibilities for competition. In carnivores, competition is often
strong and asymmetric. Africa contains one of the most species rich carnivore assemblages in the
world, where the African lion (Panthera leo) is dominant wherever it is present. Using camera trap
data on South African carnivores, we evaluated how overlap with lions in diel activity related to
similarities to lions in body mass, skull and long bone morphology. We found a positive association
between overlap in diel activity with lions and similarities in log body mass, but we only observed
this association using dry season activity data. We found no associations between overlap in diel
activity with lions and similarities in either long bone or skull morphology, nor did we find associations
between differences in overlap in diel activity within species between one reserve with and
one without lions and morphological similarity with lions. Our results suggest that niche utilization
rather than avoidance of lions dictated carnivore diel activity, although we acknowledge that
lion avoidance could have been manifested in spatial rather than temporal separation. Our study
supports recent suggestions of context dependencies in the effects of apex predator presences.
