Conservationists from the Wildlife Conservation Society and the University of St. Andrews warn that Uganda's African lions--a mainstay of the country's tourism industry and a symbol of Africa--are on the verge of disappearing from the country's national parks.
According to the results of a recent survey, African lions in Uganda have decreased by more than 30 percent over the past 10 years in some areas of the country, mostly the result of poisoning by local cattle herders, retaliations for livestock predation, and other human-related conflicts. The downward trend in lion numbers has conservationists concerned about the species' long-term chances in the country, often described as the "Pearl of Africa" for its natural wonders.
The study appears in the latest edition of the journal Oryx. The authors include: Edward Okot Omoya, Tutilo Mudumba, Paul Mulondo, and Andrew J. Plumptre from WCS and Stephen T. Buckland of the University of St. Andrews.
"African lions are a vital component of these ecosystems," said WCS conservationist Edward Okot Omoya, the lead author of the study. "They play an important role in disease control of antelopes and buffalo by killing the sick animals."
The paper describes the results of a "lure count" analysis survey to estimate the density and population distribution of lions and spotted hyenas in Uganda's three major conservation areas, conducted by researchers between November 2008 and November 2009. The researchers used a buffalo calf distress call (broadcast via speakers mounted on a vehicle roof rack) to attract both medium and large carnivores to the "call stations" as a means of calculating a current population estimate for the study locations. Previous survey methods used to count lions have included counting roars, identifying individual cats, and mark-recapture methods, but the methods are time-consuming and expensive.
Overall, the call station surveys attracted a total of 66 lions, 176 spotted hyenas, and seven leopards. The broadcasts also attracted a host of smaller predators, including side-striped jackals, black-backed jackals, white-tailed mongooses, and large spotted genets.
Using the data of animals observed, the analysis generated an estimated lion population of 408 animals in the three main strongholds for lions in Uganda, nearly two hundred fewer lions than estimates made in 2000-2002 (a statistical decrease of more than 30 percent). In Queen Elizabeth Conservation Area, estimated lion numbers have decreased from 206 to 144 over the past decade (a 30 percent drop). In Murchison Falls Conservation Area, the team estimates a nearly 60 percent drop (from 324 to 132 lions in the past decade). Only in Kidepo Valley National Park did the researchers detect an increase in estimated lion numbers (climbing from 58 to 132).
"Lions are the species tourists most want to see in Uganda's savannas according to research by WCS. Surveys of tourists have shown that they would be 50% less likely to visit the parks in Uganda if they couldn't see lions, and if they did visit they would want to pay less for the experience. As an industry that generates more foreign currency in the country than any other business this could have significant consequences for Uganda" reported Dr. Andrew Plumptre, WCS's Director for the Albertine Rift.
The study also represents the first survey of hyena numbers from these areas, generating a population estimate of 324 hyenas (the researchers suspect--but cannot prove-- hyenas to be in decline as well).
"Conservation areas such as Queen Elizabeth and Murchison Falls, which formerly contained the highest biomass of mammals on Earth, depend on the delicate balance between predators and prey," said Dr. James Deutsch, Executive Director of WCS's Africa Program. "Their loss would permanently alter two of Africa's great ecosystems."
The crisis in lion conservation in Uganda reflects the status of the species across Africa, where lion populations have dropped by 30 percent over the past two decades as a result of illegal killing and the loss of both habitat and prey. The most recent estimate of Africa's total lion population is approximately 32,000 animals. A group study led by WCS estimated that 42 percent of major lion populations are in decline. The species is nearly extinct in West and Central Africa. The species is listed as "Vulnerable" by the International Union for Conservation of Nature but there is a current proposal to list the species as "Endangered" under the U.S. Endangered Species Act because of the continuing global declines.
The Wildlife Conservation Society's Bronx Zoo exhibits African lions in its African Plains habitat, a naturalistic exhibit space that exhibits both predator and prey species separated only by moats. The Bronx Zoo's lions are part of the Species Survival Plan (SSP), a breeding cooperative administered by the Association of Zoos and Aquariums designed to enhance the genetic viability and diversity of animal populations in accredited zoos.
WCS is grateful to Panthera and the U.S. Agency for International Development for the training and funding support provided to make this research possible.