Well, not only in Uganda would you see this amazing scene, some other African Parks do have tree climbing lions. One would think lions do not climb tress but lions are capable of climbing trees and they do so when they have to. In Africa, it is speculated that lions climb trees to escape oppressive temperatures on the ground, as climbing trees means more breeze. Lions also climb trees to avoid bug bites and to get away from tse-tse flies. Maybe to also stalk prey from greater distances.
Africa National parks where lions are known for climbing trees include Serengeti National Park in Tanzania, Queen Elizabeth National Park in Uganda and Lake Manyara National Park, also in Tanzania and South Africa’s Kruger National Park.
While big body mass hampers adult lions from climbing trees, some still do. Tree-climbing lions aren’t very common, but at Ishasha Plains ( a part of the Queen Elizabeth National Park, Uganda) it’s not an uncommon sight to see even adult lions on trees. it’s cool to think of it as a cultural thing. The Tree Climbing Lions prefer Sycamore Fig and Acacia trees, I guess those trees are comfy to chill on.