IS THE NEIGHBOURHOOD GOING TO THE DOGS?
Samantha Nicholson, Lion Database Coordinator, EWT Conservation Science Unit
Carnivore species that overlap in their use of space, food or habitat are called sympatric carnivores, and competition for resources between these species can lead to conflict and death. To avoid this, species have adapted a wide range of different behavioural mechanisms to share resources, and to survive in their shared environment.
Spatial partitioning is one such mechanism, where one species will avoid an area based on another carnivore’s presence or population density. For example, among large carnivores, Lions will kill African Wild Dogs when they come into close contact, and as a result, Wild Dogs will actively spatially avoid areas where there is high Lion activity or density. Small carnivores will exhibit the same behaviour in avoidance of other carnivores. An example of this is Cape Foxes, which spatially avoid jackal core areas when foraging as they are often killed by jackals. However, some species will not exhibit this behaviour, even though there is competition. For example, neither Black-footed Cats nor Bat-eared Foxes avoid jackal core areas, even though jackals frequently kill them.
In this study, we set out to investigate the spatial relationship between Black-backed Jackals and large carnivores, to determine whether jackals use spatial partitioning at different scales to coexist with Lions and Wild Dogs. Our study was conducted in Venetia Limpopo Nature Reserve (VLNR) in Limpopo Province (South Africa). At the time of the study (2008) VLNR had a wide array of large carnivore species including Lion, Leopard, Cheetah, Spotted Hyena, Brown Hyena and Wild Dog. VLNR is a small reserve enclosed by an electrified predator-proof fence. Radio collars were fitted to three jackals from three different family groups to obtain location data. One jackal actually moved to another family group during the course of the study, which gave us data for an additional family group. At least one male and two females from each of the three Lion prides, and one dog from the single Wild Dog pack were collared.
Using the location data obtained from the collars, we calculated the annual home-range sizes of the study animals, as well as their core areas. We then compared the overlap between the three species at the home-range level (hereafter, broadscale) and the core areas (hereafter, fine scale). We found that the annual home-range sizes for the jackal groups ranged between 2.7 and 9.0 km2 while the annual home range of the pack of Wild Dogs was 339.5 km2. The annual home ranges of the three Lion prides ranged between 112.8 and 208.5 km2. Our data showed that the extent of spatial partitioning between jackals and both Wild Dogs and Lions depended on the scale at which we were looking. At the broadscale, jackals did not exhibit spatial partitioning with either of the large carnivores, meaning that there was extensive overlap between home ranges. However, when we looked at the fine scale, we found that jackals did appear to exhibit spatial partitioning. This was to be expected as both Wild Dogs and Lions kill jackals if presented with the opportunity.
Nonetheless, our study yields the first evidence of spatial partitioning between jackals and two large carnivores, and we hope future researchers will examine spatial partitioning between these species under a variety of environmental conditions across Africa, to help build a more complete understanding of their interactions.
Reference: Kamler, J. F., Nicholson, S. K., Stenkewitz, U., Gharajehdaghipour, T. & Davies-Mostert, H. T. 2020. Do black-backed jackals exhibit spatial partitioning with African wild dogs and lions? African Journal of Ecology.