Number Of Lions Research Articles

International law and lions (Panthera leo): understanding and improving the contribution of wildlife treaties to the conservation and sustainable use of an iconic carnivore

The lion (Panthera leo) is featuring ever more prominently on the agendas of international wildlife treaties like the Convention on International Trade in Endangered Species (CITES) and the Convention on the Conservation of Migratory Species of Wild Animals (CMS). Lion range and numbers have declined markedly over the last two decades. In this review we assess the present role of international wildlife treaties with a view to improving their combined contribution to the conservation and sustainable use of lions. Our analysis identifies a substantial body of relevant international wildlife law and, moreover, a significant potential for enhancing the contribution to lion conservation of these global and regional treaties. The time is right to invest in such improvements, and our review renders a range of general and treaty-specific recommendations for doing so, including making full use of the Ramsar Wetlands Convention, World Heritage Convention and transboundary conservation area (TFCA) treaties for lion conservation. The CMS holds particular potential in this regard and our analysis provides strong support for listing the lion in its Appendices.

Effective implementation of age restrictions increases selectivity of sport hunting of the African lion

Abstract Sport hunting of wildlife can play a role in conservation but can also drive population declines if not managed sustainably. Previous simulation modelling found that large felid species could theoretically be hunted sustainably by restricting harvests to older individuals that have likely reproduced. Several African countries currently use age‐based hunting for lions although the outcomes have yet to be evaluated in a wild population. Here we provide the first empirical evidence that a system of incentives sufficiently encouraged age‐based hunting and reduced offtake of a wild felid, thereby reducing the potential risk of unsustainable hunting on a threatened species. We examined long‐term hunting data and the lion population trend in Niassa National Reserve, Mozambique. To incentivise hunter compliance, a “points” system was developed, which rewards operators that harvest lions older than the 6‐year minimum trophy age recommended for sustainable hunting and penalises operators that hunt “underage” lions (<4 years). A key component of this system is the ecological application of key physical traits that predictably change with age in order to estimate (by hunters) and validate (by authorities) trophy individuals’ ages pre‐ and post‐mortem, respectively. Analysis of 138 lion hunts and 87 lion trophies from 2003 to 2015 revealed that after enforcement of age restrictions in 2006, hunters shifted harvests to suitably aged lions (>6 years), from 25% of offtakes in 2004 to 100% by 2014. Simultaneously, the number of lions and percentage of quota harvested decreased, resulting in lower lion offtakes. Following an initial decrease after enforcement of the ageing system, the percentage of hunts harvesting lions stabilised, demonstrating that hunters successfully located and aged older lions. Synthesis and applications. Evidence suggests that age restrictions combined with an incentive‐based points system regulated sport hunting and reduced pressure on the lion population. We attribute the successful implementation of this management system to: (1) committed, consistent enforcement by management authorities, (2) genuine involvement of all stakeholders from the start, (3) annual auditing by an independent third party, (4) the reliable, transparent, straightforward ageing process and (5) the simple, pragmatic points system for incentivising hunter compliance. Our study demonstrates that the use of age restrictions can increase the selectivity of sport hunting and lower trophy offtakes to reduce the possibility of unsustainable sport hunting negatively impacting species populations in the absence of reliable estimates of population size. It must be noted, however, that there was no measurable change in the lion numbers over the past decade that could be attributed to the implementation of this policy alone.

Toward accurate and precise estimates of lion density.

Reliable estimates of animal density are fundamental to understanding ecological processes and population dynamics. Furthermore, their accuracy is vital to conservation because wildlife authorities rely on estimates to make decisions. However, it is notoriously difficult to accurately estimate density for wide-ranging carnivores that occur at low densities. In recent years, significant progress has been made in density estimation of Asian carnivores, but the methods have not been widely adapted to African carnivores, such as lions (Panthera leo). Although abundance indices for lions may produce poor inferences, they continue to be used to estimate density and inform management and policy. We used sighting data from a 3-month survey and adapted a Bayesian spatially explicit capture-recapture (SECR) model to estimate spatial lion density in the Maasai Mara National Reserve and surrounding conservancies in Kenya. Our unstructured spatial capture-recapture sampling design incorporated search effort to explicitly estimate detection probability and density on a fine spatial scale, making our approach robust in the context of varying detection probabilities. Overall posterior mean lion density was estimated to be 17.08 (posterior SD 1.310) lions >1 year old/100 km2 , and the sex ratio was estimated at 2.2 females to 1 male. Our modeling framework and narrow posterior SD demonstrate that SECR methods can produce statistically rigorous and precise estimates of population parameters, and we argue that they should be favored over less reliable abundance indices. Furthermore, our approach is flexible enough to incorporate different data types, which enables robust population estimates over relatively short survey periods in a variety of systems. Trend analyses are essential to guide conservation decisions but are frequently based on surveys of differing reliability. We therefore call for a unified framework to assess lion numbers in key populations to improve management and policy decisions.

Social associations between California sea lions influence the use of a novel foraging ground.

Social relationships define an individual's position in its social network, which can influence the acquisition and spread of information and behavioural variants through the population. Thus, when nuisance behaviours spread through wildlife populations, identifying central individuals may provide valuable insights for problem-species management. We studied the effects of network position on California sea lion (Zalophus californianus) discovery and foraging success at a novel foraging ground—the salmonids that aggregate at the Bonneville Dam tail-race, 235 km up the Columbia River. We found that an individual's centrality in their social network influenced discovery of the Bonneville Dam and whether they returned the next year. Foraging success once at the dam was independent of network position. Extensive lethal and non-lethal removal efforts have been implemented at Bonneville Dam and focused on reducing the number of individual sea lions at the dam. Since social relationships forged at the opening of the Columbia River influence both the discovery and return to the Bonneville Dam, efforts to increase salmon recovery may be enhanced by breaking apart social networks at the opening of the river.

Multiple-predators-based capture process on complex networks**Project supported by the National Natural Science Foundation of China (Grant No. 61304154), the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20133219120032), the Postdoctoral Science Foundation of China (Grant No. 2013M541673), and China Postdoctoral Science Special Foundation (Grant No. 2015T80556).

The predator/prey (capture) problem is a prototype of many network-related applications. We study the capture process on complex networks by considering multiple predators from multiple sources. In our model, some lions start from multiple sources simultaneously to capture the lamb by biased random walks, which are controlled with a free parameter α. We derive the distribution of the lamb’s lifetime and the expected lifetime 〈T〉. Through simulation, we find that the expected lifetime drops substantially with the increasing number of lions. Moreover, we study how the underlying topological structure affects the capture process, and obtain that locating on small-degree nodes is better than on large-degree nodes to prolong the lifetime of the lamb. The dense or homogeneous network structures are against the survival of the lamb. We also discuss how to improve the capture efficiency in our model.

SURVEILLANCE FOR VIRAL AND PARASITIC PATHOGENS IN A VULNERABLE AFRICAN LION (PANTHERA LEO) POPULATION IN THE NORTHERN TULI GAME RESERVE, BOTSWANA.

African lion ( Panthera leo ) numbers are decreasing rapidly and populations are becoming smaller and more fragmented. Infectious diseases are one of numerous issues threatening free-ranging lion populations, and low-density populations are particularly at risk. We collected data on the prevalence and diversity of viral and parasitic pathogens in a small lion population in eastern Botswana. During 2012 and 2014, blood samples were collected from 59% (n=13) of the adult-subadult lions in the Northern Tuli Game Reserve in eastern Botswana. One lion had antibodies to feline panleukopenia virus, two had antibodies to canine distemper virus, and two had feline calicivirus antibodies. Ten of the 13 had antibodies to feline immunodeficiency virus and 11 had feline herpesvirus antibodies. All lions were negative for antibodies to feline coronavirus. Blood samples from all lions were negative for Trypanosoma, Anaplasma, Theileria, and Ehrlichia spp. by molecular testing; however, all lions were positive for Babesia spp. by reverse line blot hybridization assay. Sequencing of amplicons from four lions revealed four groups of Babesia spp. including several genetic variants of Babesia felis , Babesia lengau, and Babesia canis and a group of novel Babesia sequences which were only 96% similar to other Babesia spp. Six lions were infested with four species of ticks (Rhipicentor nuttalli, Rhipicephalus simus, Rhipicephalus sulcatus, and Rhipicephalus appendiculatus). These data provide the first health assessment of this population and can be used to identify management and conservation strategies to decrease the impact of pathogens on this population. This is particularly important as there is an initiative to incorporate this population into a larger metapopulation of lions from adjacent South Africa and Zimbabwe.

Observations of the effect of a New Year’s fireworks display on the behavior of the South American sea lion (Otaria flavescens) in a colony of central-south Chile

The use of fireworks has increased worldwide in recent years. Despite this, their effects on sea lions and similar species are almost undocumented. In this study, we documented some effects of the 2015 New Year’s fireworks on the behavior of South American sea lions (Otaria flavescens), a marine mammal species that utilizes coastal rookeries for breeding, resting, and care and nursing of pups. An immediate cessation of vocalizations followed the start of the fireworks and a significant decrease in the number of sea lions in the colony was registered. This provided evidence that fireworks disrupted the ongoing behavior of the South American sea lion. Further studies will be necessary to determine whether this disruption has negative consequences for these animals or whether they have evolved behavioral mechanisms for dealing with these kinds of short-term disruptive events.

Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus) in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

Steller sea lion (Eumetopias jubatus) numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population) in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ) was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

Autosomal and mtDNA Markers Affirm the Distinctiveness of Lions in West and Central Africa.

The evolutionary history of a species is key for understanding the taxonomy and for the design of effective management strategies for species conservation. The knowledge about the phylogenetic position of the lion (Panthera leo) in West/Central Africa is largely based on mitochondrial markers. Previous studies using mtDNA only have shown this region to hold a distinct evolutionary lineage. In addition, anthropogenic factors have led to a strong decline in West/Central African lion numbers, thus, the conservation value of these populations is particularly high. Here, we investigate whether autosomal markers are concordant with previously described phylogeographic patterns, and confirm the unique position of the West/Central African lion. Analysis of 20 microsatellites and 1,454 bp of the mitochondrial DNA in 16 lion populations representing the entire geographic range of the species found congruence in both types of markers, identifying four clusters: 1) West/Central Africa, 2) East Africa, 3) Southern Africa and 4) India. This is not in line with the current taxonomy, as defined by the IUCN, which only recognizes an African and an Asiatic subspecies. There are no indications that genetic diversity in West/Central Africa lions is lower than in either East or Southern Africa, however, given this genetic distinction and the recent declines of lion numbers in this region, we strongly recommend prioritization of conservation projects in West/Central Africa. As the current taxonomic nomenclature does not reflect the evolutionary history of the lion, we suggest that a taxonomic revision of the lion is warranted.

GrowLS: Lion (Panthera leo) Population Growth Simulation for Small Reserve Management Planning

Lion (Panthera leo) populations on small reserves (<1000 km2) require more intensive management than those in larger conservation areas. ‘Surplus’ animals are a major management concern, resulting from smaller inter-birth intervals, younger ages of first reproduction and higher survival rates. In the 1990s and early 2000s, this surplus was translocated to newly formed reserves. More recently, the proliferation of new reserves has slowed, often forcing managers to cull surplus animals. The Lion Management Forum has proposed several interventions to reduce the number of surplus lions by mimicking natural processes. These include the use of chemical contraception to increase the age of first reproduction and/or inter-birth intervals to match those found in the Kruger National Park (NP) lions; or ‘tube-tying’ to reduce litter size to match that found in the Serengeti NP. We developed a population simulation model, GrowLS, to evaluate the efficacy of these interventions. GrowLS predicts that alterations to int...

Compensating for livestock killed by lions: payment for environmental services as a policy arrangement

SUMMARYTo address human–wildlife conflicts and the related threat of extinction of the African lion, in 2003, the Maasailand Preservation Trust established a fund at the Mbirikani Group Ranch in southern Kenya to provide monetary compensation for livestock killed by wildlife. In this paper, the policy arrangement approach (PAA) is used to analyse this arrangement as a form of payment for environmental services (PES). Although there has been a considerable reduction in the number of lions killed, the analysis reveals several limitations of this arrangement, including three main side effects, namely it has initiated a process that is difficult to sustain or reverse, created a new cycle of dependence and widened the gap between different groups in the community. In conclusion, the drawbacks of this type of compensation fund must be addressed by combining such arrangements with other public and private policies and initiatives. Careful examination and comparison of different kinds of experiments with PES-like arrangements are required to further build understanding of the potential and different contributions of public and private, market-based initiatives in biodiversity governance.

A longitudinal study of Steller sea lion natality rates in the Gulf of Alaska with comparisons to census data.

Steller sea lion (Eumetopias jubatus) numbers in the Western Distinct Population Segment are beginning to recover following the dramatic decline that began in the 1970s and ended around the turn of the century. Low female reproductive rates (natality) may have contributed to the decline and remain an issue of concern for this population. During the 2000s we found high natality among Steller sea lions in the Gulf of Alaska indicating a healthy population. This study extends these previous estimates over an additional three years and tests for interannual variations and long-term trends. We further examine the proportions of pups to adult females observed on the rookery and nearby haulouts during the birthing season to assess whether census data can be used to estimate natality. Open robust design multistate models were built and tested using Program MARK to estimate survival, resighting, and state transition probabilities in addition to other parameters dependent on whether or not a female gave birth in the previous year. Natality was estimated at 70% with some evidence of interannual variation but a long-term increasing or decreasing trend was not supported by the data. Bootstrap and regression comparisons of census data with natality estimates revealed no correlation between the two methods suggesting that census data are not an appropriate proxy for natality in this species. Longitudinal studies of individual animals are an appropriate method for estimating vital rates in species with variable detection over time such as the Steller sea lion. This work indicates that natality remains high in this region and is consistent with a population in recovery.

The recovery process of a population is not always the same: The case of Otaria flavescens

Populations of the South American sea lion (Otaria flavescens) were decimated throughout its range along the Atlantic coast. Responses to this decline have been different in different parts of the species' distribution range. Some stocks are still decreasing, some remain stable, and some are recovering slowly. In the Southwestern Atlantic, sea lion populations are now increasing. However, 50 years after the cessation of hunting these populations have not recovered to the levels they had before exploitation, with the recovery process occurring at the same time as increasing development of human coastal activities. The aims of this study were to present recent information on abundance and trends in the southern Patagonian population of sea lions and to test the hypothesis of population expansion with a particular recolonization process. Results showed that there was an increase in the number of sea lions in all colonies and a change in the social composition of nine colonies, but no new breeding colonies were found. The population trajectory of O. flavescens from southern Patagonia was similar to that observed in the rest of the South Atlantic populations, but the recovery and recolonization processes are still in progress. Here we discuss possible explanations of which factors could have delayed the recovery within the Southwestern Atlantic stocks.

On tracks: A spoor-based occupancy survey of lion Panthera leo distribution in Kafue National Park, Zambia

The African lion has lost more than 75% of its historic range and numbers of wild lions continue to decline. Protected areas are critical to the species’ future, yet its conservation status in many of these presumed sanctuaries remains unknown. Zambia is one of nine countries estimated to hold over 1000 wild lions, and Kafue, its largest National Park, is a key stronghold for the species. Understanding lion distribution and threats facing the species in the park are of particular relevance given the recent ban on lion hunting in Zambia and the uncertainty over this industry’s future in the country. We used a single-season occupancy model based on detection of lion tracks to estimate proportion of area used and derive spatially explicit probability of lion use for northern Kafue, an area for which no previous empirical lion data exist. Our top-ranking model predicted that lions use 72.1% of the study area, 23.3% greater than the naïve estimate. Contrary to our expectations, and possibly due to apparent ubiquity of illegal bushmeat hunting in the park, neither prey biomass nor anthropogenic edge effects emerged as important drivers of lion distribution, with habitat class instead the best predictor. Our findings provide the management authority with survey methodology as well as focal areas for further lion research in the Kafue system. More broadly, we demonstrate the utility of track-based occupancy models in establishing the distribution of large carnivores within previously unsurveyed African protected areas.

Efficacy of Two Lion Conservation Programs in Maasailand, Kenya

Lion (Panthera leo) populations are in decline throughout most of Africa. The problem is particularly acute in southern Kenya, where Maasai pastoralists have been spearing and poisoning lions at a rate that will ensure near term local extinction. We investigated 2 approaches for improving local tolerance of lions: compensation payments for livestock lost to predators and Lion Guardians, which draws on local cultural values and knowledge to mitigate livestock-carnivore conflict and monitor carnivores. To gauge the overall influence of conservation intervention, we combined both programs into a single conservation treatment variable. Using 8 years of lion killing data, we applied Manski's partial identification approach with bounded assumptions to investigate the effect of conservation treatment on lion killing in 4 contiguous areas. In 3 of the areas, conservation treatment was positively associated with a reduction in lion killing. We then applied a generalized linear model to assess the relative efficacy of the 2 interventions. The model estimated that compensation resulted in an 87-91% drop in the number of lions killed, whereas Lion Guardians (operating in combination with compensation and alone) resulted in a 99% drop in lion killing.

Surveys of lionsPanthera leoin protected areas in Zimbabwe yield disturbing results: what is driving the population collapse?

AbstractThe African lionPanthera leois an iconic species but it has faced dramatic range reductions and possibly as few as 30,000 individuals remain in the wild. In the absence of detailed ground-based surveys, lion populations may be estimated using regression models based on prey biomass availability but these often overestimate lion densities as a result of a variety of compounding factors. Anthropogenic factors can be key drivers of lion population dynamics and in areas with high human impact lion numbers may be significantly lower than those predicted by prey biomass models. This was investigated in two protected areas in Zimbabwe, where lion population densities were found to be significantly lower than would have been predicted by prey-availability models. High hunting quotas either within or around the protected areas are the most likely cause of the low lion numbers, with quotas in some areas being as high as seven lions per 1,000 km2in some years. Other factors, including persecution, poisoning and problem animal control, as well as disease and competition with spotted hyaenasCrocuta crocuta, are also discussed.

Estimating population sizes of lions Panthera leo and spotted hyaenas Crocuta crocuta in Uganda's savannah parks, using lure count methods

AbstractDespite &gt; 60 years of conservation in Uganda's national parks the populations of lions and spotted hyaenas in these areas have never been estimated using a census method. Estimates for some sites have been extrapolated to other protected areas and educated guesses have been made but there has been nothing more definitive. We used a lure count analysis method of call-up counts to estimate populations of the lion Panthera leo and spotted hyaena Crocuta crocuta in the parks where reasonable numbers of these species exist: Queen Elizabeth Protected Area, Murchison Falls Conservation Area and Kidepo Valley National Park. We estimated a total of 408 lions and 324 hyaenas for these three conservation areas. It is unlikely that other conservation areas in Uganda host &gt; 10 lions or &gt; 40 hyaenas. The Queen Elizabeth Protected Area had the largest populations of lions and hyaenas: 140 and 211, respectively. It is estimated that lion numbers have declined by 30% in this protected area since the late 1990s and there are increasing concerns for the long-term viability of both species in Uganda.

Management of Reintroduced Lions in Small, Fenced Reserves in South Africa: An Assessment and Guidelines

Managers of African lions (Panthera leo) on reserves where they have been reintroduced increasingly face challenges associated with ecological regulation,genetic degradation and increased susceptibility to catastrophic events. The Lion Management Forum (LiMF) was formed in 2010 to define these challenges and explore possible solutions with the view to developing appropriate management guidelines. LiMF bases its recommendations on the ecologically sound premise that managers should, as far as possible, mimic natural processes that have broken down in reserves, using proactive rather than reactive methods, i.e. management should focus on causal mechanisms as opposed to reacting to symptoms. Specifically, efforts should be made to reduce population growth and thus reduce the number of excess lions in the system; disease threats should be reduced through testing and vaccination whenever animals are translocated; and genetic integrity should be monitored. The latter is particularly important, as most of these reserves are relatively small (typically <1000 km2). An adaptive management framework is needed to implement the guidelines developed here on reserves across the country, with regional nodes addressing more local genetic issues, within an overall national plan. Ongoing monitoring and scientific assessment of behavioural, population and systemic responses of lion populations and responsive modification of the guidelines, should improve management of lions on small reserves in South Africa. This approach will provide a template for evidence-based conservation management of other threatened species. Ultimately ‘National Norms and Standards’ must be established and a ‘National Action Plan’ for lions in South Africa developed.

The decline of Steller sea lions (Eumetopias jubatus) in the North Pacific: insights from indigenous people, ethnohistoric records and archaeological data

AbstractA number of hypotheses have been proposed to explain the most recent decline (1977–2012) of Steller sea lions (SSL; Eumetopias jubatus) in the Gulf of Alaska and Aleutian Islands. We examined hypotheses about fisheries competition, environmental change, predation, anthropogenic effects and disease using observations of modern Aleut and archaeological, ethnohistoric and ethnographic data from the western Gulf of Alaska and Aleutian Islands. These data indicate that Steller sea lion numbers have declined and recovered repeatedly over the past 4500 years and were last at critically low numbers during the 1870s–1930s. Steller sea lions appear to have been more abundant during the cool periods – and lower during the warmer periods. Observations by local peoples, explorers, early government surveyors and biologists since the late 1800s suggest that low populations of SSL have been associated with high populations of Gadidae fishes (Pacific cod – Gadus macrocephalus and walleye pollock – Theragra chalcogramma) and are consistent with the ocean climate hypothesis to explain the decline of sea lions. They suggest that removals by people and killer whales (Orcinus orca) did not cause the sea lion declines, but could have compounded the magnitude of the decline as sea lion numbers approached low densities. Archaeological, anthropological and ethnohistorical analyses demonstrate that fluctuations have occurred in the North Pacific over hundreds to thousands of years and provide context for understanding the changes that occur today and the changes that will continue to occur in the future.

Insights into the Management of Large Carnivores for Profitable Wildlife-Based Land Uses in African Savannas

Large African predators, especially lions (Panthera leo) and leopards (Panthera pardus), are financially valuable for ecotourism and trophy hunting operations on land also utilized for the production of other wildlife species for the same purpose. Predation of ungulates used for trophy hunting can create conflict with landholders and trade off thus exists between the value of lions and leopards and their impact on ungulate populations. Therefore productionist and conservation trade-offs are complexly graded and difficult to resolve. We investigated this with a risk-benefit analysis on a large private wildlife production area in Zimbabwe. Our model showed that lions result in substantial financial costs through predation on wild ungulates that may not be offset by profits from hunting them, whereas the returns from trophy hunting of leopards are projected to exceed the costs due to leopard predation. In the absence of additional income derived from photo-tourism the number of lions may need to be managed to minimize their impact. Lions drive important ecological processes, but there is a need to balance ecological and financial imperatives on wildlife ranches, community wildlife lands and other categories of multiple use land used for wildlife production. This will ensure the competitiveness of wildlife based land uses relative to alternatives. Our findings may thus be limited to conservancies, community land-use areas and commercial game ranches, which are expansive in Africa, and should not necessarily applied to areas where biodiversity conservation is the primary objective, even if hunting is allowed there.