Panthera leo

A species population reduction of approximately 30% is suspected over the past two decades (= approximately three Lion generations). The causes of this reduction (primarily indiscriminate killing in defense of life and livestock, coupled with prey base depletion: Bauer 2008), are unlikely to have ceased. This suspected reduction is based on direct observation; appropriate indices of abundance; a decline in area of occupation, extent of occupation and habitat quality; and actual and potential levels of exploitation.

Estimating the size of the African Lion population is an ambitious exercise involving many uncertainties. The five main efforts (Ferreras and Cousins 1996; Chardonnet 2002; Bauer and Van Der Merwe 2004; IUCN 2006a&b; Riggio et al. in press) all use different methods. The African Lion Working Group compiled individual population estimates primarily from protected areas (23,000 Lions: Bauer and Van Der Merwe 2004). In 1980, Ferreras and Cousins (1996) predicted 18,600 Lions to occur in protected areas. This was probably an underestimate as not all protected areas inhabited by Lions at that time were included. Still, the comparison suggests that the number of Lions in African protected areas has remained stable or possibly increased over time. But Ferreras and Cousins (1996) predicted that most Lions in 1980 were found outside protected areas. Chardonnet (2002) finds that unprotected areas still comprise a significant portion (half) of the Lion's current African range. Comparison of Ferreras and Cousin's (1996) prediction of 75,800 Lions in 1980 (roughly three Lion generations ago) to Chardonnet's (2002) estimate of 39,000 Lions yields a suspected decline of 48.5%. This calculation suggests a substantial decline in Lions outside protected areas over the past two decades. Ferreras and Cousins (1996) may have over-estimated the African Lion population in 1980, as their number was derived from a model rather than actual Lion counts, and so it is possible that the rate of decline of the African Lion population may be lower. A group exercise led by WCS and the IUCN SSC Cat Specialist Group estimated that 42% of major Lion populations were declining (IUCN 2006a&b, Bauer 2008). The rate of decline is most unlikely to have been as high as 90%, as reported in a series of news reports in 2003 (Kirby 2003, Frank and Parker 2003). All available data were reviewed and combined with satellite imagery leading to the most recent estimate of 32.000 lions in 67 lion areas comprising 3.4 million km², 17% of historical range or about 25% of savannah Africa (Riggio et al. in press).

In Sub-Saharan Africa, the Lion conservation community works in the context of four regions: West, Central, East and Southern. The Lion population is classified as regionally Endangered in West Africa (Bauer and Nowell 2004). It is isolated from Lion populations of Central Africa, with little or no exchange of breeding individuals (Chardonnet 2002, Bauer and Van Der Merwe 2004). The number of mature individuals in West Africa is estimated by two separate recent surveys at 850 (Bauer and Van Der Merwe 2004) and 1,163 (Chardonnet 2002). Both estimates are well below the Endangered criterion level of 2,500. Lions in West Africa are grouped into three isolated subpopulations by Chardonnet (2002) and approximately seven by the African Lion Working Group (Bauer and Van Der Merwe 2004). Chardonnet?s (2002) three subpopulations consist of 18 different individual populations, between which there may be some interchange of individuals, although this is unknown. There is disagreement over the size of the largest individual population in West Africa: the African Lion Working Group (Bauer and Van Der Merwe 2004) estimates 100 Lions in Burkina Faso's Arly-Singou ecosystem, while Chardonnet (2002) estimates 404 for the same area (mean 250).

There have been few efforts in the past to estimate the number of Lions in Africa. Myers (1975) wrote, "Since 1950, their [Lion] numbers may well have been cut in half, perhaps to as low as 200,000 in all or even less". Later, Myers (1986) wrote, "In light of evidence from all the main countries of its range, the Lion has been undergoing decline in both range and numbers, often an accelerating decline, during the past two decades". In the early 1990s, IUCN SSC Cat Specialist Group members made educated "guesstimates" of 30,000 to 100,000 for the African Lion population (Nowell and Jackson 1996).

The most quantitative historical estimate of the African Lion population in the recent past was made by Ferreras and Cousins (1996), who developed a GIS-based model to predict African Lion range and numbers, calibrated by surveying experts about the factors affecting Lion populations. First they correlated vegetation (Leaf Area Index) with Lion densities, using known values from 37 studies in 19 African protected areas, and mapped potential Lion range. Then the reduction effect of human activities on Lion range and numbers were estimated. Lion experts were surveyed in order to develop and rank a set of factors which would lead to lower Lion densities as well as Lion absence. These included agriculture, human population density, cattle grazing, and distance from a protected area, and were derived from GIS databases of varying age. For example, in areas identified as main cattle grazing areas Lion density was reduced by 90%, and in areas identified as having widespread agricultural cultivation or high human population density (> 2.5 people/km²) Lions were considered absent. Lion density was reduced by 50% in areas with low human population density (1-2.5 people/km²). Because of the age of their data sources on extent of agriculture and pastoralism, Ferreras and Cousins (1996) selected 1980 as the base year for their predicted African Lion population of 75,800. They emphasized the need for ground-truthing their estimate by censusing Lions, particularly outside protected areas.

Two recent surveys have provided current estimates of the African Lion population, with some ground-truthing. The African Lion Working Group, a network of specialists affiliated with the IUCN SSC Cat Specialist Group, conducted a mail survey and compiled estimates of 100 known African Lion populations. Not included were populations of known existence, but unknown or unestimated size. The ALWG African Lion population estimate is 23,000, with a range of 16,500-30,000 (Bauer and Van Der Merwe 2004). The second survey was carried out by Philippe Chardonnet and sponsored by the International Foundation for the Conservation of Wildlife and Conservation Force (Chardonnet 2002). He also compiled estimates for 144 individual African Lion populations, grouped into 36 largely isolated subpopulations. His methodology included extrapolation of estimates of known populations into areas where Lion status was unknown, and his total figure is not surprisingly larger: 39,000 Lions in Africa, with a range of 29,000-47,000.

Approximately 30% of the individual population estimates compiled by the African Lion Working Group were based on scientific surveys. Techniques for these surveys included total count based on individually identified body features, sampling by use of calling stations playing recordings of hyaena and/or Lion prey, and mark-recapture methods including radio telemetry, photo databases, and spoor counts (Bauer and Van Der Merwe 2004). Seventy percent of their population figures were derived from expert opinion or guesstimate. In the other survey, 63% of Chardonnet's (2002) individual population estimates were based on expert opinions or guesstimates. Twelve percent of Chardonnet's (2002) estimates were based on scientific surveys, and a further 25% were derived from extrapolation of variables from nearby populations and catch-per-unit effort-estimates based on Lion trophy hunting.

Estimating the size of the African Lion population is an ambitious exercise involving many uncertainties. The three main efforts (Ferreras and Cousins 1996; Chardonnet 2002; Bauer and Van Der Merwe 2004) all use different methods. The African Lion Working Group compiled individual population estimates primarily from protected areas (23,000 Lions: Bauer and Van Der Merwe 2004). In 1980, Ferreras and Cousins (1996) predicted 18,600 Lions to occur in protected areas. This was probably an underestimate as not all protected areas inhabited by Lions at that time were included. Still, the comparison suggests that the number of Lions in African protected areas has remained stable or possibly increased over time. But Ferreras and Cousins (1996) predicted that most Lions in 1980 were found outside protected areas. Chardonnet (2002) finds that unprotected areas still comprise a significant portion (half) of the Lion's current African range. Comparison of Ferreras and Cousin's (1996) prediction of 75,800 Lions in 1980 (roughly three Lion generations ago) to Chardonnet's (2002) estimate of 39,000 Lions yields a suspected decline of 48.5%. This calculation suggests a substantial decline in Lions outside protected areas over the past two decades. Ferreras and Cousins (1996) may have over-estimated the African Lion population in 1980, as their number was derived from a model rather than actual Lion counts, and so it is possible that the rate of decline of the African Lion population may be lower. A group exercise led by WCS and the IUCN SSC Cat Specialist Group estimated that 42% of major Lion populations were declining (Bauer 2008). The rate of decline is most unlikely to have been as high as 90%, as reported in a series of news reports in 2003 (Kirby 2003, Frank and Parker 2003).

Genetic population models indicate that large populations (50-100 Lion prides) are necessary to conserve genetic diversity and avoid inbreeding, which increases significantly when populations fall below 10 prides. Male dispersal is also an important factor in conserving genetic variation (Bjorklund 2003). These conditions are met in few wild Lion populations, although there are at least 17 Lion "strongholds" >50,000 km² in extent (Bauer 2008).

Outside sub-Saharan Africa, the Asiatic Lion P. leo persica occurs as an isolated single wild population in India's GirForest. The Gir Lion population had been reduced to a very low number in the early years of the 20th century, possibly fewer than 20. In 1936, 234 Lions were estimated, falling to approximately 100 iin the 1970s, and estimates in the 1980s and 1990s around 200 adults (Nowell and Jackson 1996). In 2005, the population was estimated at 359, +/- 10, including cubs, based on, according to the Chief Minister of Forests for Gujarat state, a total count of Lions by direct sighting in a block-system methodology. This is an increase from 327 reported in 2001 (Anon. 2006). The Wildlife Protection Society of India reported 34 Lion deaths in 2007, due to poaching, electrocution, falling into open wells, and death by motor vehicle and unknown causes. Single populations are vulnerable to extinction from catastrophic events, and it has long been recommended by scientists to establish a second wild population in Madhya Pradesh's Kuno Wildlife Sanctuary, but this has not yet been done (Jackson 2008). The Asiatic Lion shows reduced genetic variation due to small population size (O'Brien et al. 1987). It is feared that the size of the population is larger than the estimated carrying capacity of the habitat and prey base (Nowell and Jackson 1996).

For further information about this species, see Mammals/15951_Panthera_leo.pdf.

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The Lion has a broad habitat tolerance, absent only from tropical rainforest and the interior of the Sahara desert (Nowell and Jackson 1996). There are records of Lion to elevations of more than 4,000 m in the BaleMountains and on Kilimanjaro (West and Packer in press). Although Lions drink regularly when water is available, they are capable of obtaining their moisture requirements from prey and even plants (such as the tsama melon in the Kalahari desert), and thus can survive in very arid environments. Medium- to large-sized ungulates (including antelopes, zebra and wildebeest) are the bulk of their prey, but Lions will take almost any animal, from rodents to a rhino. They also scavenge, displacing other predators (such as the Spotted Hyaena) from their kills.

Lions are the most social of the cats, with related females remaining together in prides, and related and unrelated males forming coalitions competing for tenure over prides. Average pride size (including males and females) is four to six adults; prides generally break into smaller groups when hunting. Lions tend to live at higher densities than most other felids, but with a wide variation from 1.5 adults per 100 km² in southern African semi-desert to 55/100 km² in parts of the Serengeti (Sunquist and Sunquist 2002). Pride ranges can vary widely even in the same region: e.g., from 266-4,532 km² in the Kgalagadi Transfrontier Park of South Africa (Funston 2001), and 20,500 km² in the Serengeti (West and Packer in press).

In India, the habitat of the Asiatic Lion is dry deciduous forest. The GirNational Park and Wildlife Sanctuary is surrounded by cultivated areas and inhabited by the pastoralist Maldharis and their livestock. Domestic cattle have historically been a major part of the Asiatic Lion's diet, although the most common prey is the chital deer. Mean pride size, measured by the number of adult females, tends to be smaller than for African Lions: most Gir prides contain an average of two adult females (Nowell and Jackson 1996).

The main threats to Lions are indiscriminate killing (primarily as a result of retaliatory or pre-emptive killing to protect life and livestock) and prey base depletion. Habitat loss and conversion has led to a number of populations becoming small and isolated (Bauer 2008).

The economic impact of stock raiding can be significant: Patterson et al. (2004) estimated that each Lion cost ranchers in Kenya living alongside Tsavo East National Park US$290 per year in livestock losses. Likewise, annual losses of cattle to Lions in areas adjacent to WazaNational Park in Cameroon comprised only about 3.1% of all livestock losses, but were estimated to represent more than 22% of financial losses amounting to about US$370 per owner (Bauer 2003). Consequently, Lions are persecuted intensely in livestock areas across Africa; their scavenging behaviour makes them particularly vulnerable to poisoned carcasses put out to eliminate predators. Little actual information exists on the number of Lions killed as problem animals by local people, even though this is considered the primary threat to their survival outside protected areas. Implementation of appropriate livestock management measures, coupled with problem animal control measures and mechanisms for compensating livestock losses, are some of the primary responses to resolving human-Lion conflict (Frank et al. 2006).

Trophy hunting is carried out in a number of sub-Saharan African countries and is considered an important management tool for providing financial resource for Lion conservation for both governments and local communities. However, there is concern that current management regimes can lead to unsustainable offtakes (Packer et al. 2006).

Disease has also been a threat to Lion populations (Ray et al. 2005).

In parts of southeastern Tanzania there have been alarmingly high incidences of people killed by Lions, with up to 400 human Lion-related fatalities recorded from 1997-2007 (Ikanda 2007).

P. leo is included in CITES Appendix II; the Endangered Asiatic Lion subspecies P. leo persica is included in CITES Appendix I.

In Africa, Lions are present in a number of large and well-managed protected areas, and remain one of the most popular animals on the must-see lists of tourists and visitors to Africa. Most range states in East and Southern Africa have an infrastructure which supports wildlife tourism, and in this way Lions generate significant cash revenue for park management and local communities and provide a strong incentive for wildland conservation.

Regional conservation strategies have been developed for Lions in west and central Africa (IUCN 2006a) and eastern and southern Africa (IUCN 2006b). The West and Central African Lion Conservation Strategy focuses on three primary objectives to address threats that directly impact Lions: to reduce Lion-human conflict, and to conserve and increase Lion habitat and wild prey base. The objectives of the Eastern and Southern African Lion Conservation Strategy are articulated around the root issues in Lion conservation, including policy and land use, socio-economics, trade, and conservation politics. For example, the policy and land use objective is "to develop and implement harmonious and comprehensive legal and institutional frameworks that provide for the expansion of wildife-integrated land use, Lion conservation and associated socio-economic benefits in current and potential Lion range." The trade objective is "to prevent illegal trade in Lions and Lion products while promoting and safeguarding sustainable legal trade." Both regional strategies share common priorities of conserving and restoring Lion populations, improving management capacity, and increasing the flow of benefits to communities living with Lions. These strategies should be used by governments to guide national Lion action plans, policies and programs, and by the conservation community to guide their project development. By setting out common priorities to guide action on both national, community and landscape levels, the regional conservation strategies have the potential for broad and significant improvement of Lion status and management (Nowell et al. 2006).

For the Asiatic Lion, resolving human Lion-conflict is a high priority, as well as establishing a second wild population (Jackson 2008).