Population size, density, and ranging behaviour in a key leopard population in the Western Cape, South Africa

Abstract

Globally, leopards are the most widespread large felid. However, mounting anthropogenic threats are rapidly reducing viable leopard populations and their range. Despite the clear pressures facing this species, there is a dearth of robust and reliable population and density estimates for leopards across their range, which is particularly important in landscapes that consist of protected and non-protected areas. We conducted a camera trapping survey between 2017 and 2018 in the Western Cape, South Africa to estimate the occupancy, density, and population size of a leopard population. Leopards were recorded at 95% of camera trapping sites, which resulted in a high occupancy that showed no significant variation between seasons, habitat types, or along an altitudinal gradient. Our results indicated a low leopard density in the study area, with an estimated 1.53 leopards/100 km2 in summer and 1.62 leopards/100 km2 in winter. Mean leopard population size was therefore estimated at 107 and 113 individuals in the winter and summer respectively. Leopard activity centres for female ranges were centred in the core study area and could be predicted with good certainty, while males appeared to move out of the study area during winter which resulted in a higher uncertainty in locations of activity centres. Interestingly, livestock depredation events in the surrounding farmlands were significantly higher in winter, which coincides with male leopards moving outside the core protected area into the surrounding farmlands. To reduce livestock losses and retaliatory leopard killings, we suggest that human-carnivore conflict mitigation measures be intensely monitored during the winter months in the study area. We also suggest that future leopard conservation efforts should focus on privately-owned land as these non-protected areas contain the majority of the remaining suitable leopard habitat and may provide important dispersal corridors and buffer zones on which the long-term sustainability of leopard populations depends.

Assessment of leopard translocations in South Africa

“…Some authors have recommended moving leopards at least 200 km from the capture site to prevent capture site fidelity and homing instinct (Weise et al, 2015a;Briers-Louw et al, 2019). It would seem prudent to lean towards developing translocation distances of greater than four diameters of the regionally known localized leopard home ranges-for instance, based on the leopard home range size in the southern provinces of South Africa (Devens et al, 2018;Müller et al, 2022), our findings support the consideration of translocation distances between 200 and 400 km in these provinces.…”

“…Therefore, the wide-range nature of leopards contributes to the outcome of translocations. This is relevant to the home range sizes of leopards which vary greatly across various bio-regions, depending on pray resources, land cover types, topography, and social structures, with some leopards requiring small home ranges of <20 km², while others require >1,000 km² (e.g., le Roux and Skinner, 1989;Bailey, 1993;Mondal et al, 2013;Weise et al, 2015a;Devens et al, 2018;Müller et al, 2022). As such, regional variations of leopard spatial requirements should be considered when planning an appropriate translocation distance.…”

“…Weise et al (2015a) mitigated these challenges and demonstrated success in the repeated release of individuals into the same geographic region by releasing individuals into a receiving population with low to moderate densities of conspecifics and by ensuring at least 6 months of inter-release period for individuals to assimilate the additional leopards. Further considerations should include the asymmetrical dispersal behavior of leopards, whereby male individuals are primarily the dispersing sex, moving vast distances compared to female leopards (Fattebert et al, 2013;Elbroch et al, 2016;Sunquist and Sunquist, 2017;Müller et al, 2022). Female individuals are generally philopatric and influence the local structure of populations and their dynamics (Elbroch et al, 2016;McManus et al, 2021).…”

“…In South Africa, most leopard habitats exist outside of protected areas, where HCC is high (Swanepoel et al, 2013;McManus et al, 2021;McManus et al, 2022). The lack of connectivity between isolated, low-density populations of South Africa's Eastern and Western Cape provinces contributes to reduced gene flow (McManus et al, 2014;Devens et al, 2018;Mann et al, 2020;Devens et al, 2021;Müller et al, 2022).…”

Facilitation of a free-roaming apex predator in working lands: evaluating factors that influence leopard spatial dynamics and prey availability in a South African biodiversity hotspot

“…Our setup procedures followed standard protocols optimised for the detection of leopards, whereby the landscape across both study regions was divided into 50 km 2 blocks ( Fig. 1 ), based on the minimum estimated home range size recorded for a female leopard with cubs in the Western Cape (37 km 2 ; Martins, 2010 ; also see Müller et al, 2022a , 2022b ). Camera-trap stations were dispersed across mountainous habitat with mean distances of 2.78 km (Cederberg) and 3.09 km (Piketberg) between individual stations and two to three stations per block ( Fig.…”