Resource Partitioning of Sympatric African Wolves (Canis lupaster) and Side-Striped Jackals (Canis adustus) in an Arid Environment from West Africa

Abstract

Knowledge on interference competition between species, particularly for scarce crucial resources, such as water, is a topic of increasing relevance for wildlife management given climate change scenarios. This study focuses on two sympatric canids, the African wolf and the side-striped jackal, to evaluate their group size and spatiotemporal activity patterns in the use of a limited resource by monitoring artificial waterholes in a semi-arid environment located in Senegal (West Africa). Remote cameras were deployed at five artificial waterholes to evaluate the number of individuals, age and activity patterns of resource use. African wolves (n = 71; 31% of all carnivore detections) and side-striped jackals (n = 104; 45%) were the most detected carnivore species. While both canids tended to occur alone at waterholes, they showed an evident monthly variation in group size. Both species showed a high activity overlap, with a bimodal activity pattern in waterhole use. However, we found evidence of unidirectional spatiotemporal avoidance, suggesting African wolves might be dominant over side-striped jackals. Our findings provide useful insights to investigate niche partitioning on the use of limited resources and have conservation implications for regions with a prolonged dry season.

Temporal niche partitioning between carnivores differs depending on the analytical method: comparison between temporal overlap and co-occurrence, and time-to-encounter analyses

“…Indeed, Karanth et al 34 found a large overlap in diel activity patterns between tigers (Panthera tigris) and leopards (Panthera pardus), while demonstrating their behavioral avoidance by using the time-to-encounter analysis. Similarly, Paúl et al 39 also found a large overlap in diel activity patterns between side-striped jackals (Canis adustus) and African wolves (Canis lupaster), while indicating the occurrence of some behavioral avoidance using the time-to-encounter analysis, with side-striped jackals taking longer than expected to be detected after the occurrence of African wolves. These results suggest that the evaluation of behavioral avoidance at ne time scales using the time-to-encounter analysis may provide an understanding of the mechanisms of species coexistence that cannot be detected by only estimating the temporal overlap.…”

“…4 and 5). However, many previous studies disregarded the effects of this order 34,37,38,68 (but also see Paúl et al 39 ). This study suggested the necessity of the time-to-encounter analysis with the species-occurrence order replacement, if the competitive dominances among focal species are not clear.…”

“…To determine competitive dominances among the three target species, we considered the before/after occurrence (e.g. red fox (before) -raccoon dog (after), raccoon dog -red fox) for the detected species when calculating the time-to-encounter across each species pair 39 . For this procedure, we created matrix of detection records for each species consisting of the camera-trap site, date, and time.…”

“…For example, if two species are both nocturnal, a subordinate (i.e., smaller) species may coexist with a dominant species by avoiding direct encounters with the larger competitor at ne time scale (e.g., dozens of minutes or several hours), even if the coe cient of temporal overlap shows a high value 34 . Nowadays, the spatio-temporal niche partitioning has been measured to assess behavioral avoidance by focusing on the time-to-encounter between individuals of different species (e.g., [34][35][36][37][38][39][40] ). Indeed, Karanth et al 34 found a large overlap in diel activity patterns between tigers (Panthera tigris) and leopards (Panthera pardus), while demonstrating their behavioral avoidance by using the time-to-encounter analysis.…”