Number Of Lions Research Articles

Disruption of an ant-plant mutualism shapes interactions between lions and their primary prey.

Mutualisms often define ecosystems, but they are susceptible to human activities. Combining experiments, animal tracking, and mortality investigations, we show that the invasive big-headed ant (Pheidole megacephala) makes lions (Panthera leo) less effective at killing their primary prey, plains zebra (Equus quagga). Big-headed ants disrupted the mutualism between native ants (Crematogaster spp.) and the dominant whistling-thorn tree (Vachellia drepanolobium), rendering trees vulnerable to elephant (Loxodonta africana) browsing and resulting in landscapes with higher visibility. Although zebra kills were significantly less likely to occur in higher-visibility, invaded areas, lion numbers did not decline since the onset of the invasion, likely because of prey-switching to African buffalo (Syncerus caffer). We show that by controlling biophysical structure across landscapes, a tiny invader reconfigured predator-prey dynamics among iconic species.

Long-term remote monitoring of the rookery of Eumetopias jubatus (Pinnipedia, Otariidae) on Matykil Island in the Magadan State Nature Reserve (Russia)

The severe decline in the number of Eumetopias jubatus (hereinafter – Steller sea lion) almost throughout the entire range has drawn the public attention to monitor the abundance and increase in research activity of the species. In Russia, such a study has been conducted regularly since the early 2000s. It includes range-wide population surveys in the Russian Far East, marking newborn pups and monitoring their survival, movements, and reproduction success. In the first decade of the XXI century, observers conducted direct observations on rookeries during the breeding season. Since 2011 a novel survey method has been used, using custom-made autonomous high-resolution remote cameras, which have been taking images of the rookeries all year round. In 2013, six remote-camera units were installed in the Magadan State Nature Reserve (Russia) at the rookery of the Steller sea lion located on Matykil Island. The cameras gathered images during day time every 5–30 min. Maintenance of the photo recorders was carried out once per year in the summer period. A total of 721 927 photographs were collected during eight years of the surveys. Of them, 60 632 photographs were manually analysed in this research. It was found that the Steller sea lions use the rookery throughout the year, with the exception of March when a dense and wide ice cover in the study area prevents the Steller sea lions from reaching the shore of Matykil Island. During the year, two peaks of the Steller sea lion population abundance were observed, namely summer and, with a higher number of individuals, in autumn. In summer, females predominate on the rookery, while in the autumn-winter period, young animals (mainly males) and mature (8+ years) adults. In winter, the number of Steller sea lions was low on the shore. We have seen branded Steller sea lions on Matykil Island from all rookeries in the Russian Far East, with the exception of animals born on the Commander Islands. The highest number of migrant Steller sea lions appears in the autumn period, and it is represented mainly by young animals (1–3 years old) and semi-adults (males aged 4–7 years). In general, the data obtained from images collected by remote cameras during the entire year provided a detailed picture of the rookery used by Steller sea lions during the entire annual cycle of their life and monitored the seasonal population dynamics, the sex and age composition of animals on the shore, and the reproductive success of marked Steller sea lions. Currently, the use of autonomous remote cameras remains the only available method of year-round monitoring of the state and habitat use of hard-to-reach remote Steller sea lion’s rookeries.

A review of field techniques to estimate lion presence and abundance

Abstract Since the 1990s, the number of lions (Panthera leo) has declined by about 43% across African range states. Reliable lion population estimates can contribute to effective management and inform local and international conservation policies. Though many survey methods have been used to estimate lion abundance, an assessment of their usefulness and effectiveness is lacking. We reviewed and identified available methods used to estimate lion populations, then investigated their feasibility, cost‐effectiveness and suitability to achieve primary objectives. We identified 12 methods in two categories: direct (minimum counts, call‐in surveys, capture–recapture, opportunistic sightings, remote cameras, distance‐based and aerial counts) and indirect (track counts, secondary information, prey‐based, genetic samples and roar counts). We identified 48 studies (57%) in which lion population estimation was not repeatable. Additionally, 38% did not provide any measure of precision. About 28% of the studies were conducted specifically for management purposes, while remaining studies focused on population estimates and dynamics. Because data from these studies have influenced local management and global lion conservation policies, we recommend basing future policies and management on repeatable, precise and accurate population estimates supported by appropriate and cost‐effective experimental designs. In most cases, these estimates are obtained through actual lion counts derived from direct observation methods including call‐in, capture–recapture and remote camera surveys or through reliable animal signs such as genetic samples.

Distribution and Abundance of California (Zalophus californianus) and Steller (Eumetopias jubatus) Sea Lions in the Inshore Waters of Washington, 2013-2016

Two species of sea lions occur in the in387land waters of Washington State: the California sea lion (Zalophus californianus) and the Steller sea lion (Eumetopias jubatus). Both species breed elsewhere, but they typically move into Puget Sound and adjacent waters of the Salish Sea from autumn through spring. There is a need for information on their current abundance and seasonal use patterns as both species prey heavily on threatened/endangered stocks of salmon and steelhead trout (Oncorhynchus spp.), and empirical abundance estimates of these species are lacking for inland Washington waters. From 2013 to 2016, we conducted 39,399 km of aerial surveys for marine mammals in this area, sighting 255 groups of sea lions. We used a subset of 7,841 km of effort and 165 sea lion sightings made during surveys in good sighting conditions to estimate in-water abundance using line-transect methods. Historical tagging data collected in Pacific Northwest waters were used to evaluate the proportions of time that each species spent on land and conducting dives, and then to develop correction factors to derive total abundance for both sea lion species, providing the first empirical abundance estimates for these waters. We estimated that between 33 and 442 California sea lions were found in Puget Sound/Hood Canal in different seasons, with nearly 3,000 being found in the broader inland Washington waters in the peak season (spring). Steller sea lions occurred in much smaller numbers, with a peak of 219 animals in Puget Sound/Hood Canal/Strait of Juan de Fuca in autumn (and possibly as many as 600 to 700 in the entire study area). While some estimates suffer from low precision, this study demonstrates that substantial numbers of sea lions use waters of the study area throughout much of the year. Our results provide an important step toward a better understanding of these two species in the inland waters of Washington, as well as their potential effects on protected salmonid prey species.

Twenty years of lion conservation in a commercial rangeland

Lion populations in Africa declined precipitously in the twentieth century outside of protected areas but the commercial cattle ranches of Laikipia County, Kenya, have been a unique exception, with low livestock stocking rates, careful range management, large populations of wild ungulates, and a full complement of large carnivores, including lions at a stable density of about 6/100 km2. The Laikipia Predator Project, later Living With Lions, started in 1997 with two primary objectives: improving livestock husbandry to reduce lion predation losses and subsequent killing of lions, and studying behavioral adaptations of lions to human activities and persecution. We initially interviewed ranch owners and managers on lion numbers, losses to all mortality factors, husbandry methods, costs, and lion control measures. Studies of husbandry and control methods led to improved livestock management, which gradually reduced losses and retaliatory lion killing. Persecuted lions are secretive and nocturnal, so behavioral research was dependent upon radio collaring, requiring development an effective capture technique. Collars introduced ranchers to their lions as individuals, decreasing their propensity to shoot them after livestock predation. The most important breakthrough was the development of “lion-proof” mobile bomas (corrals) which dramatically reduced night time losses and retaliatory killing. Global positioning system (GPS)-Iridium collars for research into lion movements, allowed development of a Lion Early Warning System to inform ranchers of morning lion locations, allowing them to avoid lions during day time grazing. These measures reduced retaliatory lion killing by 90% between 1998 and 2017. Development of simple and inexpensive hyena-proof bomas for traditional pastoralists dramatically reduced their losses and motivation to poison predators. Studies of lion movements and ecological energetics in relation to human activities have revealed patterns of diel avoidance of humans/livestock by day and predation of wild prey near bomas at night, showing that lions partition their activities temporally in order to utilize high quality hunting habitat while minimizing risk of encountering humans. Studies of predation ecology suggest that lion predation does not have a significant impact on Laikipia’s important population of endangered Grevy’s zebra. Several other carnivore research and conservation projects in Kenya arose out of the initial work in Laikipia.

The extent and nature of the commercial captive lion industry in the Free State province, South Africa

The captive breeding of wildlife for commercial purposes is a controversial issue. In South Africa, the farming of African lions (Panthera leo) for commercial trade emerged in the early 1990s, partly as a conservation measure to reduce the decline in wild lion numbers while meeting increasing wildlife trade demands. In May 2021, the South African Department of Forestry, Fisheries, and the Environment (DFFE) announced plans to end the captive breeding of lions, keeping of lions in captivity, and the use of captive lions, their parts and derivatives for commercial trade. Here, we examined the commercial captive lion industry from 2017 to 2020 in the Free State province, the heart of the lion breeding industry. We document the extent of the industry and highlight a number of key management issues. Of particular concern were issues with microchip numbers, which are used to follow each registered lion from birth to death through the system and to avoid laundering of wild caught and/or non-registered lions. Of the 4,823 unique microchips that were identified, at least 11% could not be followed through the system. Additionally, a minimum of 199 microchip numbers may have been reused by permit holders, either on captivity, euthanasia, or transport permits, indicating potential non-compliance with the Threatened or Protected Species (TOPS) Regulations. We highlight further areas of concern that warrant additional attention for these types of activities that may cause management issues during the transition period and which may also be relevant for the keeping, breeding, and trading of other TOPS regulated species in South Africa, particularly big cat species.

Managed culls mean extinction for a marine mammal population when combined with extreme climate impacts

Human actions led to the worldwide decline of marine mammal populations in the 18th–19th centuries. Global adoption of protective legislation during the 20th century has recently allowed many marine mammal populations to recover. This positive trend is particularly true of pinnipeds (e.g., seals and sea lions), whose recovering populations are increasingly in conflict with fisheries. Fisheries organisations have called for managed culls of sea lion populations to reduce competition for target fish species as well as damage to catch and fishing gear through operational interactions. However, despite widespread perceptions that sea lion populations are generally increasing, to-date, culls have often been considered or implemented without quantitative evidence of their impacts on seal lion population viability. This knowledge gap is particularly concerning given the expected increase in extreme climate conditions, such as extreme El Niño events, which together with culls could push sea lion populations in some parts of the world into the extinction vortex. Here, I develop stochastic matrix population models of the South American sea lion (Otaria flavescens) parameterised through a combination of species-specific field data and phylogenetic imputation using data from related species in the COMADRE animal matrix database. Using these models, I project the impact of (1) three cull scenarios with different intensity and temporal frequency targeting adult females, (2) extreme El Niño events whose frequency is modelled using a Markovian transition matrix, and (3) the interaction of culls and extreme climate events on population dynamics. I focus on the Chilean population of O. flavescens, where recent increases in sea lion numbers have triggered widespread conflict with small-scale fisheries, and where sea lion populations will increasingly be affected by extreme El Niño conditions. I find that sea lion populations decline below minimum viable population sizes within 16–28 years under all scenarios involving culls and extreme climate events. This research explicitly incorporates parameter uncertainty into population projections—in so doing, it illustrates the need for future research to collect stage-specific, annual population data to reduce uncertainty regarding marine mammal vital rates.

English

African lion (Panthera leo), is an important species in the Ethiopian ecosystems. However, significant lion populations and their suitable habitats in many of their former ranges in Ethiopia have declined over time due to socioeconomic uncertainty and the resulting ecological imbalances. Despite this general trend, it is equally noted that there is a lack of verifiable data which depicts the past and current status of African lions. Thus, very little is known about the species in question in most of its ranges. Available published and unpublished reports and manuscripts on the target species were reviewed in order to examine and document the status of the African lion in Ethiopia. From our review, we concluded that the lion numbers are still low and declining whilst considerable ranges have been identified through the field assessments conducted in the last two decades. African lions in Ethiopia have been under serious threat from various anthropogenic activities and it is therefore recommended to effectively implement the national conservation action plan for lion and undertake further field assessment on its habitats. This study suggests the establishment of a national Red list category for the threatened species based on the final reports of our assessments.   Key words: Trends, abundance, distribution, threats, conservation.

What is a lion worth to local people – Quantifying of the costs of living alongside a top predator

The presence of large predators entails a range of costs and some benefits for the communities that live alongside them. The cost in terms of the value of livestock lost to predation is well known, but this represents only a part of the costs that people experience, as it does not account for non-market costs such as fear, avoidance behaviours and threat to human life. We quantify the total cost of lion presence for agro-pastoral communities in Zimbabwe using economic valuation techniques. The total perceived value of one additional lion was estimated to be negative US$180 per person per year, which is several hundred times larger than the market value of the average loss of livestock per household. If making simplifying economic assumptions, this discrepancy reveals the magnitude of the non-market costs associated with the presence of large predators. The disvalue of lion presence was linked to fear, ecocentric values, wealth and trust in compensation institutions. We also demonstrate the importance of considering heterogeneity in preferences within communities; segments of the population did not have net negative value attached to lions, and some disliked monetary compensation. We also estimate the willingness-to-accept for two human-wildlife conflict mitigation programs in terms of acceptable increases in lion numbers, as opposed to monetary units which is the conventional approach in economic valuation studies. We argue that estimating value in terms of biodiversity outcomes should be used more widely. We also demonstrate the distorting effect of distrust towards compensation in choice experiments and argue that economic valuation methods employing choice experiments should control for this distrust when estimating willingness-to-pay. These discoveries have relevance for a wide range of situations where potentially dangerous wildlife species co-exist with people.

The impacts of management interventions on the sociality of African lions (Panthera leo): Implications for lion conservation

Abstract African lion (Panthera leo) populations normally consist of several neighbouring prides and multiple adult males or groups of males that interact competitively. In large, open systems, cub defence from infanticidal males and territory defence drive group living in lions. However, in smaller (<1000 km2), fenced wildlife reserves, opportunities for natural immigration and emigration are limited which means that the evolutionary drivers of lion sociality may collapse. Here, we use lion behavioural data collected from 16 wildlife reserves across South Africa to test how management‐induced ecological conditions alter lion social dynamics. The number of lionesses observed together was best predicted by pride size, prey biomass and biome. Lionesses were less likely to group together as pride size increased, but more likely to group together as prey biomass and habitat productivity increased. In addition, adult males were observed more frequently with prides that had young (<12 months) cubs in reserves that had unfamiliar adult males present compared to reserves without any unfamiliar adult males. Our results demonstrate how intraspecific competition between lions drives their sociality, and this may break down in small, fenced wildlife reserves where lions are actively managed. Although small, fenced reserves in South Africa have made a significant contribution to increasing lion numbers on the continent, our work highlights several important ecological implications of active lion management. For wildlife managers, mimicking the outcomes of different levels of intraspecific competition is likely a critical management tool for the persistence of lions in small reserves.

African Lion Population Estimates in Tanzania’s Ruaha National Park

Tanzania is considered a country with the largest number of African lions (Panthera leo). However, the continued absence of ecological population estimates and understanding of the associated factors influencing lion distribution hinders the development of conservation planning. This is particularly true in the Ruaha-Rungwa landscape, where it was estimated that more than 10% of the global lion population currently resides. By using a call-back survey method, we aimed to provide population estimates (population size and density) of African lions in the Ruaha National Park, between wet (March 2019) and dry (October 2019) seasons. We also assessed the key factors that influenced the distribution of the observed lions towards call-back stations. Ferreira & Funston’s (2010) formula was used to calculate population size and in turn used to estimate density in the sampled area, while the Generalized Linear Model (GLMM) with zero-inflated Poisson error distribution was used to determine factors that influence the distribution of the observed lions to call-back stations. The population size we calculated for the sampled area of 3137.2 km2 revealed 286 lions (95% CI, 236 - 335) during the wet season, and 196 lions (95% CI, 192 - 200) during the dry season. The density of lions was 9.1/100 km2 during the wet season, and 6.3/100 km2 during the dry season. Distance to water source had a significant negative effect on the distribution of the observed lions to the call-back stations, while habitat had a marginal effect. Our findings show that, although lion population estimates were larger during the wet season than the dry season, the season had no effect on the distribution of the observed lions to call-back stations. We suggest that the proximity to water sources is important in study design. Further, we suggest that density and population size are useful indices in identifying conservation area priorities and lion coexistence strategies.

Long‐term abundance dynamics of the South American sea lion (Otaria flavescens) in the most important breeding colony in central Chile

AbstractLong‐term studies that monitor changes in the abundance of pinnipeds are particularly relevant given that these long‐lived species are considered to be indicators of the quality of the ecosystems around them. We report a continuous record of the total abundance by sex and age‐classes of the South American sea lion (Otaria flavescens) in Cobquecura, the most important breeding colony in central Chile over a twelve‐year period (2008 to 2020). We also analysed the demographic trends in South American sea lion abundance at this location. A total of 110 and 43 sea/land based and aerial censuses were performed over the studied period, respectively. The number of sea lions on land was highest in the summer months, which corresponds to the breeding season of the species. The abundance ranged from a minimum of 870 to a maximum of 4,531 individuals from sea/land‐based observations, and from 796 to 4,854 from aerial censuses. This variation was mainly influenced by the number of adult females, the most abundant age‐class in the colony. On the contrary, adult and sub‐adult males were least abundant in the population. The highest numbers of pups were registered in February of each year, ranging from 448 in February 2009 to 1,214 in February 2017. During the study period, we estimated a finite growth rate (λ) of 1.031, suggesting an increase in the population size in the colony, especially in the number of pups. Considering Cobquecura is highly susceptible to anthropogenic disturbance, developing effective long‐term protection through adequate management is critical to better conserve the South American sea lion in the most important breeding colony in central Chile.

A Burning Question: Can Savannah Fire Management Generate Enough Carbon Revenue to Help Save the Lion from Extinction?

Lions (Panthera leo) in Africa have lost nearly half their population in just the last two decades, and effective management of the protected areas (PAs) where lions live will cost an estimated USD >$1 B/year in new funding. We explore the potential for launching a fire management and habitat restoration carbon-financing program to help fill this PA management funding gap. We demonstrate how introducing early dry season fire management programs could produce potential carbon revenues (PCR) from either a single carbon-financing method (avoided emissions) or from multiple sequestration methods of USD $59.6-$655.9 M/year (at USD $5/ton) or USD $155.0 M–$1.7 B/year (at USD $13/ton). We highlight variable but significant PCR for PAs with the greatest potential for restoring lion numbers between USD $1.5–$44.4 M per PA. We suggest investing in lion-centric fire management programs to jump-start the United Nations Decade of Ecological Restoration and help preserve African lions across their range.

Threat analysis for more effective lion conservation

AbstractWe use comparable 2005 and 2018 population data to assess threats driving the decline of lion Panthera leo populations, and review information on threats structured by problem tree and root cause analysis. We define 11 threats and rank their severity and prevalence. Two threats emerged as affecting both the number of lion populations and numbers within them: livestock depredation leading to retaliatory killing of lions, and bushmeat poaching leading to prey depletion. Our data do not allow determination of whether any specific threat drives declines faster than others. Of 20 local extirpations, most were associated with armed conflicts as a driver of proximate threats. We discuss the prevalence and severity of proximate threats and their drivers, to identify priorities for more effective conservation of lions, other carnivores and their prey.

Managing hunting quotas of African lions (Panthera leo): A case study from Zambia

Hunting lions while their populations are declining in much of Africa is a highly controversial issue. However, hunting for lions and other charismatic large mammals in Africa has contributed to maintaining large areas of wild land for lions and wildlife conservation. To minimise the impacts of hunting lions in some 150,000 km2 of Game Management Areas (total ∼190,000 km2) in Zambia an age-based quota setting system has been adopted. The approach involves reducing the number of lions taken to one per hunting block and limiting trophy hunting to past prime male lions. The age-based assessment criteria and the results from assessing the trophies taken in 2017 and 2018 are presented. Of the 18 trophies taken in 2017, 11% were judged to be under age, 17% were marginal and the remaining 72% were acceptable trophies of animals aged 6 years or older, with 28% being ≥7 years or older. The results for 2018 showed a higher proportion (42%) of older lions (≥7 years) being taken. Legal instruments to give force to the guidelines on trophies that can legally be hunted are being introduced to ensure the sustainable offtake of past prime male lions with minimal disruption of pride coalitions. These developments will contribute to improved management of lion hunting in Zambia and to meeting the non-detriment finding and conservation enhancement requirements of European and American regulations governing the importation of lion trophies.

A citizen science approach to monitoring of the Lion Panthera leo (Carnivora: Felidae) population in Niokolo-Koba National Park, Senegal

A voluntary citizen science approach was used in a pilot study of the relict population of the Critically Endangered western African Lion Panthera leo in Niokolo-Koba National Park (NKNP) in Senegal. In total, 93 observations involving 253 lion sightings were made by NKNP guides and their clients over a period of four and a half years in the central tourist area of the Park which represents about 3% of the total area of NKNP. Identification sheets were produced for 10 individual lions on the basis of whisker spot patterns measured from photographs contributed by the tourists. Although we were not able to identify a sufficient number of individual lions to estimate the lion population in the zone, extensive data on the geographic distribution, age-class and sex, and behaviour of the observed lions are presented. Data are also presented to tentatively support a relationship between the annual variations in lion observations and the total rainfall in the preceding year. The advantages of this citizen science approach in terms of complementing mainstream science, as well as in promoting tourism development and conservation sensitisation, are discussed, and recommendations are made for pursuing this cooperative effort at a higher level of effectiveness.

Lions, Bylaws, and Conservation Metrics

Abstract African lions are a significant threat to pastoralists, triggering both retaliatory and nonretaliatory killings that represent a high-profile example of human–wildlife conflict. In the present article, we report on a grassroots campaign to reduce such conflict by shifting agropastoralists’ attitudes toward lion killing and the central role of bylaws in its apparent success. Insofar as all of East Africa's principal protected areas still harboring lions are surrounded by pastoralist populations, the vast majority of which persecute lions, this novel strategy is of considerable wide-scale and practical significance. We report on an estimated 59%–69% reduction in the number of lions killed since the implementation of bylaws and use our experiences to highlight the need for fresh dialog among project managers, conservation organizations, and their funders in crafting appropriate conservation success metrics. In the context of human–wildlife conflict, changes in peoples’ norms and attitudes are of greater significance over the long term than simplistic tabulations of the number of individuals saved.

Toxocariasis In A Lioness In Jos Zoo, Nigeria

Wild animals in Zoos across the globe are kept for aesthetic, educational, recreational and conservation purposes. Collections of rare and endangered species are also preserved in Zoos. Lions do well in captivity but are prone to excessive worm burden especially round worms and tapeworms though these conditions can easily be managed with adequate Veterinary services. Incidence of toxocariasis in captive African lions (Panthera leo) in Nigeria has largely not been reported. Jos Zoo and Wildlife Park both in Plateau State of Nigeria have lost significant number of lions to toxocariasis due to inadequate Veterinary attention A fatal case of toxocariasis in an African Lioness in Jos Zoological Garden, Nigeria was presented as a case study.

Conservation conundrum: Endangered predators eating endangered prey

Conservation conundrum: Endangered predators eating endangered prey

Anthropogenic disturbance induces opposing population trends in spotted hyenas and African lions

Large carnivore populations are declining worldwide due to direct and indirect conflicts with humans. Protected areas are critical for conserving large carnivores, but increasing human-wildlife conflict, tourism, and human population growth near these sanctuaries may have negative effects on the carnivores within sanctuary borders. Our goals were to investigate how anthropogenic disturbance along the edge of the Masai Mara National Reserve, Kenya, influences the demography and space-use of two large carnivore species that engage in intense interspecific competition. Here we document, in one disturbed region of the Reserve, a rapid increase in the population size of one large predator, the spotted hyena (Crocuta crocuta), but a striking concurrent decline in numbers of another, the African lion (Panthera leo). Anthropogenic disturbances negatively affected lion populations, and decreasing lion numbers appear to have a positive effect on hyena populations, indicated here by an increase in juvenile survivorship. We also saw an increase in the number of livestock consumed by hyenas. Our results suggest human population growth and indirect effects of human activity along Reserve boundaries may be effecting a trophic cascade inside the Reserve itself. These results indicate both top-down and bottom-up processes are causing a shift in the carnivore community, and a major disruption of guild structure, inside the boundaries of one of the most spectacular protected areas in Africa.