The Ecology and Management of Kalahari lions in a Conflict Area in Central Botswana

Abstract

African Lions (Panthera leo) are an keys species in many natural ecosystems in Africa and provide income and ecosystem services to many human communities. They directly limit herbivore populations, which in turn maintain grasslands and associated systems. Those ecosystems have degraded in recent decades and the concurrent decline in lion population is believed to play a role. I investigated factors affecting lion behaviour and ecology including the effect of seasonal variation in wild prey herd size. Current levels of herbivore prey are significantly lower than before the creation of countrywide veterinary cordon fences and total lean season biomass was estimated at 375.5 kg.km-2. I placed GPS position locating radio collars on 13 lions in 6 prides in a study area of approximately 9,911 square kilometres in the north of the Central Kalahari Game Reserve (CKGR), in central Botswana. The collars acquired total of 241,858 usable GPS fixes and I visited each lion monthly. Lion spatial behaviour appears to have changed in response to the decline in herbivores, although there is only a small amount of historical data. Lion home ranges were large (mean home range = 2116.5 km2, range 798.3- 4243.7 km2) compared to two prides from a study in the 1970s in the same area which had home ranges of approximately 337 km2. Those prides increased their range to today’s sizes only in severe drought years, but rainfall during the study period was high. I interpret this as evidence that seasonal lower herbivore densities have increased lion ranges, and reduced the number of lions in the CKGR. I estimate the current population in the study area at 307 adult lions, or 3.1 lions per 100km2. During months of high herbivore group densities, lions travelled further on a daily basis (mean daily movement distance of 7,160 m at lowest density, to 8,616 m at the highest density), and males on average travelled significantly further each day than females (mean of 10,071.6m per day for male, SD = 7099.4, maximum 48,462m and a mean of 7,633.6m per day for females, SD= 5,069.3m, maximum 29,470m). Females moved similar distances daily even while supporting cubs under 3 months old. Lions significantly preferred hunting prey species above 90kg, but also hunted the smaller warthog (Phacochoerus africanus) and African porcupine (Hystrix africaeaustralis). This has implications for conflict mitigation and lion conservation. I investigate the economics and extent of the lion livestock conflict in Central Botswana and explore potential management options in light of this new data. Management options should be carefully selected with consideration for economics, politics and local conditions, and should target locations where conflict mitigation can have the greatest benefit for both lion conservation and economic improvement of stakeholders in order to have the best chance for success. not a change in reserve management. After carefully examining the ecology of the Central Kalahari lions and the management of the reserve and farms in the area, I conclude that mitigating lion-livestock conflict is best achieved through improving grazing practices and not a change in reserve management.