Lion (Panthera Leo), cattle and wildlife interactions on the Kuku Group Ranch Pastoralist Area, Kenya

Abstract

Globally, large carnivores populations are declining with dramatic effects on lower trophic levels. As apex predators, large carnivores play critical roles in ecosystem processes, and unnatural declines in large carnivore populations can adversely affect their ecosystems. The reasons for declining carnivore numbers are numerous. However, one of the main threats to carnivores is human-wildlife conflict. Increases in human-wildlife interactions can pose significant threats to human safety and domestic livestock, causing conflict. Global human-wildlife conflicts have increased drastically over the last decade, and the countries of East Africa experience some of the highest rates of carnivore and other wildlife conflicts in the world. Lions are often the cause of conflict with livestock-owning people outside of formally protected areas when they often prey upon livestock, causing financial loss and negative perceptions, which frequently leads to their destruction. It is essential to understand why lions are involved in human-wildlife conflicts and the drivers of such conflict. East Africa is home to three lion strongholds in Africa, including the study site within The Kuku Group Ranch (KGR). The KGR is a community-owned area covering 1 133 km², located near the Kenya-Tanzania border. The KGR is a wildlife corridor linking the Tsavo West, Amboseli, Chyulu Hills, and Kilimanjaro national parks. KGR is crucial for maintaining healthy wildlife populations, including a lion population, and preserving natural ecological processes in the area. However, lion populations are more frequently coming into contact with humans due to livestock and human expansion in the group ranch. Livestock expansion increases pressure on lion populations, and conflicts where lions are killed due to cattle depredations, are becoming commonplace. Viable lion populations present in the KGR suggest that lions can survive if the conflict rate between cattle owning people and lions is slowed. But the situation requires research as no formal, standardised investigations into the diets of lions and the drivers of cattle depredation have been conducted. Therefore, the primary aim of this study was to investigate lion diet and prey preference in the KGR, a communal mixed-use area. The secondary aim was to understand how rainfall, lag rainfall (the average of the preceding two months and current months rainfall), Normalized Difference Vegetation Index (NDVI) and prey availability variables affected cattle depredation rates over 36 months in the KGR. Drivers that affected cattle depredation were investigated by modelling how variables influenced cattle depredation rates. Information on lions' diets was obtained from an investigation of predicted lion feeding sites obtained from location data of lions fitted with satellite collars (n = 7). Potential feeding sites were identified by analysing Global Positioning System (GPS) data points to identify positions where three or more consecutive GPS fixes were less than 100 m apart, and lions spent longer than 9 hours consecutively. Two data sources were used to estimate prey availability. Biannual aerial counts for overall prey availability, while community ranger patrol data provided continuous monthly data on prey availability in the form of monthly encounter rates per km. Data collected on lion diet and prey availability allowed preference calculations to discern which prey was most consumed and preferred. Prey preference was calculated using the Jacobs index for prey selectivity. GPS cluster analysis resulted in 112 confirmed feeding events where large-bodied prey species (>50Kg) could be identified to species level. Cattle (Bos taurus), plains zebra (Equus quagga), Coke's hartebeest (Alcelaphus cokeii), Maasai giraffe (Giraffa tippelskirchi), blue wildebeest (Connochaetes taurinus), and eland (Tragelaphus oryx), made up 92% large-bodied prey consumed. The most common species consumed by lions were cattle (74%). The four most important wild prey species contributing to lion prey biomass were the Maasai giraffe, plains zebra, eland and Coke's hartebeest. These four species are also the most frequently encountered wild large prey species in the KGR. An analysis of cattle depredation data for the KGR resulted in 330 cattle depredations sites. Field investigation of the 330 sites resulted in 176 negligent events and 154 non-negligent events. To identify drivers of cattle depredation, General Linear Modelling was used to compare rainfall, lag rainfall, NDVI and prey availability (predictor variables) to the number of cattle depredation events recorded every month over 36 months. The most important driver of cattle depredation was lag rainfall. During higher periods of lag rainfall, cattle depredation doubled. Although only displaying weak relationships, cattle depredations increased with increasing NDVI and decreased with a concurrent increase in wild prey availability. Lions consumed high cattle numbers, and increases in lag rainfall drove rates of cattle depredation. The survival of lions in Africa and Kenya will be dependent on the ability of NGO's, governmental agencies, and local communities to prevent, mitigate, and address human-lion conflicts. Identifying the drivers of human-wildlife conflicts here can assist conservationists and communities in better understanding and minimising the risk of cattle depredations. Improving husbandry practices during the periods of higher lag rainfall and protecting large-bodied wild prey populations are management interventions likely to maintain lion populations and improve conservation in the KGR communal area. Improving these factors can preserve wildlife corridors and sustain diverse, ecologically functional mammal assemblages that can disperse to and from the surrounding national parks.