Detecting declines of apex carnivores and evaluating their causes: An example with Zambian lions

Abstract

a b s t r a c tLarge carnivores are in rapid global decline, with a broad array of consequences for the ecosystems they inhabit. To efficiently detect and address these declines requires unbiased and precise demographic data. Unfortunately, the characteristics that make large carnivores extinction-prone also pose serious challenges to obtaining these data. Rapid survey methods exist, but provide only relative measures of abundance, cannot detect declines before they become large, and provide little or no information about the causes of decline. African lions (Panthera leo) are declining throughout their range, making accurate monitoring of remaining populations urgent. We provide statistically rigorous estimates of population size, trends, survival rate and age-sex structure from Zambia's South Luangwa lion population from 2008 to 2012, just prior to cessation of hunting in 2013. Mark-recapture models fit to data from intensive monitoring of 210 individual lions in 18 prides and 14 male coalitions indicated a declining population, low recruitment, low sub-adult and adult male survival, depletion of adult males, and a senescing adult female population. Trophy hunting was the leading cause of death, with 46 males harvested. Based on these data we recommend continuing the hunting ban at least to 2016 to allow recovery, with substantially reduced quotas, age-limits, and effective trophy monitoring mandated thereafter should hunting resume. Similar data from intensive monitoring of key Zambian lion populations is required to evaluate effects of the hunting ban and provide management guidance. Effectively integrating intensive long-term monitoring and rapid survey methods should be a priority for future management and monitoring of carnivore species.

Effects of a protection gradient on carnivore density and survival: an example with leopards in the Luangwa valley, Zambia

“…Although most of SLNP is surrounded by GMAs, human encroachment is increasing with demonstrated effects on other carnivores. The drivers of these effects include illegal bushmeat harvest (Lewis and Phiri 1998;Becker et al 2013a;Lindsey et al 2013;Watson et al 2013), high levels of legal trophy and resident hunting (Yamazaki 1996;Becker et al 2013b;Rosenblatt et al 2014), and habitat conversion (Watson et al 2014). Therefore, SLNP and adjacent GMAs provide an opportunity to compare leopard densities and survival rates between a fully protected area with relatively minimal impact by humans, and an immediately adjacent buffer zone with growing direct and indirect anthropogenic effects.…”

Density and population structure of the jaguar (Panthera onca) in a protected area of Los Llanos, Venezuela, from 1 year of camera trap monitoring

“…Conversely, carnivore populations with few breeding individuals may have a higher extinction risk. Thus, integrating methods to estimate large carnivore population breeding structure with density could improve population trend predictions and promote effective conservation (Woodroffe 2011;Rosenblatt et al 2014).…”

Lion ( Panthera leo ) populations are declining rapidly across Africa, except in intensively managed areas

“…The African lion (Panthera leo) exemplifies the challenges of carnivore conservation: widespread habitat loss (4), extensive prey base depletion (5-7), indiscriminate retaliatory or preemptive killing to protect humans and their livestock (8)(9)(10), poorly regulated sport hunting (11)(12)(13)(14)(15)(16)(17)(18), and demand for traditional African and Chinese medicines (19). Although lions are relatively well-studied compared with most large felids, regional-scale population estimates remain scant across much of its range (20), and population surveys are generally repeated at irregular intervals because of the inherent difficulty of counting lions (21,22) and shortage of funds for systematic surveys.…”