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).

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.