Zimbabwe Wild Dogs

Counting lions in Savé Valley Conservancy

During the last few years, conservationists have become aware that African lions are declining in both total population size and distribution at an alarming rate. Previously, lions were thought to be in fairly good shape in conservation terms and so the species was largely neglected while most conservation focus was given to vulnerable cheetahs and endangered wild dogs, both of which are much rarer. However, it is now apparent that intervention is required to halt or at least slow the decline before lions do face a more serious conservation predicament. Latest estimates put the number of lions at somewhere between 16,500 and 40,000 lions, down from an estimate of 30,000-100,000 in 1996. The wide variation between methods is due to different census methods being used, but also due to the difficulty associated with counting carnivores over such vast areas. What is clear though is that the population trajectory is down. The primary causes for the decline in lion populations include: conflict between people and lions over livestock, habitat destruction and the loss of wild prey due to unsustainable bush meat hunting. Fortunately for the species, where lions and their prey are adequately protected (such as in most national parks), lions tend to do very well. Savé Valley Conservancy is no exception.

Prior to the formation of the conservancy, lions were made virtually extinct in the area through persecution by cattle ranchers protecting their stock. Since then though, lions have started to naturally re-colonize the area from Gonarezhou National Park to the south. Initially, the lion population was very slow to increase as most of the individuals re-colonizing the area were nomadic males who found it difficult to find female lions. Over time though, small groups of females filtered through into the area and the population started to increase more quickly. Then, in 2005, a pride of 10 lions were reintroduced into the northern half of the conservancy. Sadly, shortly after release, disaster struck: at least two of the adult females were killed in poachers’ snares shortly after release. Thankfully though, the remainder survived and are breeding well.

Last year, we counted the lions using a combination of call-ups (where noises of dying lion prey were played at high volume through speakers in the bush, attracting lions, which we then counted) and spoor counts. The spoor count method worked best and in April this year, we will repeat the census. Last year, we counted 48 lions which was up from the 25 or so counted in the previous census. This year, we expect the population to have increased significantly again. Lions have the potential to increase in number rapidly under the right conditions, and given the amount and quality of habitat present in Save Conservancy, ultimately, we can expect to see a population of somewhere between 200-300 lions, which would be of major conservation significance.

However, such a large lion population would undoubtedly have a negative impact on the wild dog population of SVC. Lions kill wild dogs, adults and pups when they get chance. Perhaps more serious is that wild dogs tend to select for habitats that have low lion densities so as to avoid contact with them. This means that they are forced to occupy areas with lower densities of prey and suffer greater exposure to snares and other forms of human disturbance. A key component of our research is to assess the impact of the increasing lion population on the behavioural ecology and conservation of the wild dogs.

Prior to the re-colonization of the area by lions, the wild dogs exhibited several characteristics that were suggestive of ‘competitive release’ – or freedom from competition with lions. Some of these included: home ranges falling in areas with highest prey densities, relatively small pack sizes and very high pup survival rates. As the lions increase, we now expect to see the wild dogs using more marginal habitat (i.e. with lower prey densities, and possibly areas outside the conservancy), larger pack sizes (necessitated by the need to protect pups at the den) and lower pup survival rates. Hopefully, by gaining a better understanding of the relationship between wild dogs and lions we will be able to contribute to understanding of how to manage the species in protected areas. The significance of competition between lions and wild dogs is that wild dogs tend not to do well in protected areas with lots of lions. This means that conservation strategies for wild dogs have to focus a lot on finding ways for wild dogs to survive, and coexist with people outside of parks networks.