Visit Queen Elizabeth National Park in Uganda or Lake Manyara National Park in Tanzania and you’ll see something unusual: lions that climb trees and spend a good part of their lives resting on branches high above the ground. Elsewhere, lions rarely climb and look rather silly when they try to do so.
“They can get up there pretty well,” said Craig Packer, who oversaw the Serengeti Lion Project for some 35 years. But he added that “they get up there and then they’re like, ‘Whoa, how do I get down?’”
Other big predatory cats climb trees all the time. “Anatomically, leopards are just better built for climbing,” said Luke Hunter, executive director of the big cats program of the Wildlife Conservation Society in New York City. “They’re lighter, and a leopard’s scapula, their shoulder blades, are proportionally bigger, flatter and more concave than a lion’s.
“Lions, on the other hand, are built with enormously powerful forequarters, and a very, very stiff back,” he continued. “That’s for wrestling heavyweight prey, such as a buffalo, to the ground.” Their enormous power, he added, “comes at the cost of the agility and the vertical power that a leopard has in being able to whip up a tree with an impala.”
Climbing a tree, Dr. Packer said, can even be dangerous, especially for heavier male lions. “Coming down, a lion could dislocate a limb with all that weight.”
Most lions also have little need to climb trees. They are social and live in prides and can generally defend their meals from other predators. Solitary leopards must stash their kills somewhere safe and would, according to one study, lose more than one-third of their kills to hyenas if they were unable to hoist their captured prey up a tree.
So why do lions in some areas climb trees, if they’re not built to climb and rarely need to do so? It has less to do with natural abilities and more to do with learned behaviors and unique local conditions.
In Zimbabwe, there are very few records of lions climbing trees, said Moreangels Mbizah, a conservation biologist working with lions in the Kavango-Zambezi Transfrontier Conservation Area. “The only reason they would want to climb is if there is something on the ground that they’re avoiding,” she said.
After a period of particularly heavy rainfall in 1963, for example, a plague of Stomoxys biting flies drove lions up trees and down warthog burrows, anywhere to escape the insects that caused open wounds and deadly infections. This learned habit, George B. Schaller speculated in “The Serengeti Lion,” a seminal study of lion behavior, may have been the precursor to the culture of tree climbing among Lake Manyara’s lions.
Lions may also climb trees to escape the heat and survey the landscape for prey, says Joshua Mabonga, carnivore research coordinator with the Uganda program at the Wildlife Conservation Society. But in Queen Elizabeth National Park in Uganda, there may be another reason: Lions there live in smaller prides than those in many other lion habitats and share the park with large herds of buffaloes and elephants. When faced with a stampede of buffaloes who may endanger them, lions escape up into the branches. “The safest place for lions is in the trees,” Mr. Mabonga said.
Or, as Dr. Packer put it, “Lions climb trees to escape pests, whether they’re as big as an elephant or as small as a stable fly.”
For lions to be able to make such an escape, they need the right sort of tree. Lions often climb African sycamore fig trees or umbrella acacia thorn trees, which have horizontal branches not too far above the ground.
“It makes it really easy for lions to climb and get up,” Dr. Hunter said.
Where lions have acquired a taste for the experience, and conditions exist allowing them to climb, they have taken to tree climbing with the leopard-like zeal of converts. In Queen Elizabeth National Park, Dr. Hunter said: “You get entire families — adults, youngsters, everyone — up trees. Generation after generation, it really has become a habit to go up in the trees. It just gets entrenched as a culture because it’s fun.”