Lion (Panthera leo) populations are declining rapidly across Africa, except in intensively managed areas

Abstract

We compiled all credible repeated lion surveys and present time series data for 47 lion (Panthera leo) populations. We used a Bayesian state space model to estimate growth rate-λ for each population and summed these into three regional sets to provide conservation-relevant estimates of trends since 1990. We found a striking geographical pattern: African lion populations are declining everywhere, except in four southern countries (Botswana, Namibia, South Africa, and Zimbabwe). Population models indicate a 67% chance that lions in West and Central Africa decline by one-half, while estimating a 37% chance that lions in East Africa also decline by one-half over two decades. We recommend separate regional assessments of the lion in the World Conservation Union (IUCN) Red List of Threatened Species: already recognized as critically endangered in West Africa, our analysis supports listing as regionally endangered in Central and East Africa and least concern in southern Africa. Almost all lion populations that historically exceeded ∼ 500 individuals are declining, but lion conservation is successful in southern Africa, in part because of the proliferation of reintroduced lions in small, fenced, intensively managed, and funded reserves. If management budgets for wild lands cannot keep pace with mounting levels of threat, the species may rely increasingly on these southern African areas and may no longer be a flagship species of the once vast natural ecosystems across the rest of the continent.

Keywords: Africa; Panthera leo; lion; population decline.

Fig. 1.

Distribution map of monitored lion populations; zooming levels: (A) species wide, (B) East Africa, (C) West Central Africa, (D) southern Africa. 1, Gir; 2, Murchison Falls; 3, Laikipia; 4, Samburu; 5, Queen Elizabeth National Park; 6, Ol Pejeta Conservancy; 7, Masai Mara; 8, Nairobi; 9, Serengeti; 10, Ngorongoro; 11, Mbirikani; 12, Tarangire; 13, Taita Hills; 14, Katavi; 15, Matambwe; 16, Luangwa; 17, Niassa; 18, Niokolo Koba; 19, Comoe National Park; 20, Mole; 21, Pendjari; 22, W; 23, Kainji Lake; 24, Yankari; 25, Waza; 26, Benoue; 27, Kunene; 28, Etosha; 29, Ongava; 30, Okavango Delta; 31, Chobe Kwando; 32, Hwange; 33, Makgadikgadi Pans; 34, Save Conservancy; 35, Malilangwe Conservancy; 36, Bubye Conservancy; 37, Gonarezhou; 38, Kruger National Park; 39, Kgalagadi; 40, Madikwe Nature Reserve; 41, Welgevonden; 42, Makalali; 43, Pilanesberg National Park; 44, Tembe Elephant Park; 45, Phinda; 46, Hluhluwe iMfolozi; and 47, Kwandwe.

Fig. 2.

Posterior densities of growth rates for (A) West Central Africa lion populations and (B) special cases. The gray areas under the curves indicate the probabilities of decline. Values shown are medians ± SDs of growth rate estimates.

Fig. 3.

Posterior densities of growth rates for East Africa lion populations. The gray areas under the curves indicate the probabilities of decline. Values shown are medians ± SDs of growth rate estimates. *Fenced populations.

Fig. 4.

Posterior densities of growth rates for southern Africa lion populations. The gray areas under the curves indicate the probabilities of decline. Values shown are medians ± SDs of growth rate estimates. *Fenced populations.

Fig. S1.

West Central African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals).

Fig. S1.

West Central African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals).

Fig. S2.

East African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals). *Fenced populations.

Fig. S2.

East African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals). *Fenced populations.

Fig. S3.

Southern African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals). *Fenced populations.

Fig. S3.

Southern African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals). *Fenced populations.

Fig. S3.

Southern African populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals). *Fenced populations.

Fig. S4.

Other populations: model fitted to time series (black squares are data, white circles are medians of the model-inferred true population sizes μ_t, and gray areas between dashes lines are 95% credible intervals).

Fig. S5.

Patterns of information in the time series data. Each site is represented by the number of years with and without data in its time series, and each point is scaled according to population size. Populations are grouped according to our modeled growth rate estimates. The area above the solid diagonal line indicates populations with times series that lack data for more than one-half of the years. The area below the solid diagonal lines indicates populations with data from more than one-half of the years in the time series. Dotted diagonal lines indicate the overall span of each time series. For example, a 10-y time series (including years with missing data) is indicated by the line having 10 as x and y intercepts.