Washington, December 5: About 75 percent of Africa’s savannahs and more than two-thirds of the lion population once estimated to live there have disappeared in the last 50 years, a study, led by Duke University researchers, has revealed.
The study estimates the number of lions now living on the savannahs to be as low as 32,000, down from nearly 100,000 in 1960. Lion populations in West Africa have experienced the greatest declines.
“The word savannah conjures up visions of vast open plains teeming with wildlife. But the reality is that massive land-use change and deforestation, driven by rapid human population growth, has fragmented or degraded much of the original savannah. Only 25 percent remains of an ecosystem that once was a third larger than the continental United States,” said Stuart Pimm, Doris Duke Professor of Conservation Ecology at Duke’s Nicholas School of the Environment.
Pimm and his colleagues used high-resolution satellite imagery from Google Earth, coupled with human population density data and estimates of local lion populations, to map areas still favourable to the big cats’ survival.
They identified only 67 isolated areas of savannah across the continent with suitably low human impacts and densities.
Of these, only 10 spots were deemed to be “strongholds” where lions have an excellent chance of survival. Many of the strongholds are located within national parks.
None of the strongholds is located in West Africa, where human populations have doubled in many countries over the last 20 to 30 years. The new study suggests fewer than 500 lions remain in this region, and they are scattered across eight isolated sites.
“Existing maps made from low-resolution satellite imagery show large areas of intact savannah woodlands. Based on our fieldwork in Africa, we knew they were wrong,” explained lead author Jason Riggio, a former member of Pimm’s lab who is now a PhD student in ecology at the University of California at Davis.
“Using very high-resolution imagery we could tell that many of these areas are riddled with small fields and extensive, if small, human settlements that make it impossible for lions to survive,” he said.
Andrew Jacobson, a member of Pimm’s lab noted “Giving these lions something of a fighting chance will require substantial increases in effort. The next 10 years are decisive for this region, not just for lions but for biodiversity, since lions are indicators of ecosystem health.”
The finding was published this week in the journal Biodiversity and Conservation. (ANI)