Famed Tree-Climbing Lions Running Low on Prey

By Stephanie Pappas, Live Science Contributor | May 12, 2017 07:06am ET 

A rare group of tree-climbing lions living in Uganda must range farther and farther to find enough prey to survive, a new study found.

The research discovered that the lions of the country's Ishasha district have expanded their ranges and shrunk the size of their prides since the 1970s. The lions live in Queen Elizabeth National Park and are one of only two populations of lions in the world that climb trees daily, according to the park. (The other group lives in a park in Tanzania.) The lions may climb to avoid the heat at ground level or to escape from biting flies. Their unusual behavior makes them a major tourist draw for Uganda.

Poaching in the park has slashed the biomass, or total weight, of prey animals for the lions, like antelope, down from 50,7000 lbs. per 0.6 square miles (23,000 kilograms per square kilometer) in the 1970s to just 17,750 lbs. per 0.6 square miles (8,050 kg per square km) today, researchers from the Wildlife Conservation Society wrote in the Journal of East African Natural History.

Home on the range

To find out how the animals have adapted, the researchers fitted radio collars to 12 lions from the two prides in Ishasha and followed the big cats between 2005 and 2010. The scientists used the radio collar data to determine the lions' home ranges, calculating the distances roamed both for the pride as a whole and for individual lions.

The data showed that the ranges of the prides today vary between 18.7 square miles (48.5 square km) and 22.6 square miles (58.5 square km). In the mid-1970s, Ishasha lions stuck a little closer to home: The northern pride had an average range of 13 square miles (34 square km), while the southern pride stayed within an area of 14.7 square miles (38 square km), the researchers said. These are already small range sizes for lions, the researchers wrote; in the Serengeti, lions sometimes roam over 155 square miles (400 square km). 

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