No abstract

2016-12-23T18:52:10

Apex carnivores around the world have experienced rapid population declines and local extirpation due to anthropogenic pressures, and they are increasingly restricted to government-protected areas (GPAs). Though GPAs are critical for carnivore conservation, mixed-use landscapes may be crucial for sustaining viable populations. Few studies, particularly in Africa, have examined joint use of a landscape by people and conflictprone carnivores, such as the African lion (Panthera leo), in a situation where conflict is low. In southern Kenya, we studied a lion population in an unfenced rangeland occupied by the Maasai people and their livestock. The Maasai shift their settlements and grazing areas seasonally across a permanent river, a practice we hypothesized might promote coexistence. We radio-collared lions (n = 6) to determine density and document spatial patterns in response to seasonal movements of people in a Conservation Area and buffer zone (250 km 2). Despite high livestock density, lion density was comparable to many GPAs (0.136 individuals/km 2). Lion spatial distribution and habitat selection shifted in relation to seasonal movements of people and livestock. Conflict was low, likely because lions increased their use of the Conservation Area and dense habitats when people were nearby. Lion responses to human movements reduced access to permanent water, but not prey. A land use system based on temporary settlements and grazing areas allowed lions to co-occur with people and livestock at high density. These results suggest a general strategy for the conservation of apex carnivores outside of GPAs, focusing on areas that exhibit spatiotemporal variation in human land use.

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.

Globally, large carnivores are declining due to direct persecution, habitat loss, and prey depletion. The effects of prey depletion could be amplified by changes in the composition of the herbivore (prey) community that provoke changes in carnivore diets, but this possibility has received little attention. We tested for changes over the past half‐century in prey selection by the large carnivore guild in Zambia's Kafue National Park (KNP). Across 52 predator–prey dyads, 71% of the observed changes showed that large prey have become less important and small prey have become more important. Consequently, dietary niche breadth has decreased for KNP carnivores and niche overlap has increased. We tested whether changes in the importance of prey species are related to their current abundance and uniformly found that prey that have increased in importance are now relatively common, while those that have decreased in importance are now relatively rare. We identify four potential effects of these changes for conservation (through intraguild competition, group size, the energetics of hunting, and vulnerability to snaring) that warrant investigation. Synthesis and applications. Patterns of prey selection by the large carnivores in Kafue National Park (KNP) have changed appreciably over the past half‐century. Decreased predation on large prey, which are now relatively rare, has caused niche compression and increased overlap in carnivore diets. Predation by all KNP large carnivores now concentrates on four small prey species that remain relatively abundant (impala, puku, lechwe, and warthog). Methods to detect such changes in interactions between species are well‐established, but are rarely applied to large carnivore‐ungulate systems. To guide conservation of ecosystem function, monitoring programmes should consider whether prey depletion alters the patterns of predation or competition within the predator guild because these interactions strongly affect the distribution and abundance of both predators and prey. If the patterns seen in KNP are general, then where carnivores are limited by prey depletion, conservation efforts will be most effective if they focus on mitigating the loss of large prey. In KNP, targeted efforts to protect prey larger than 200 kg, particularly buffalo, should be a priority.