Why Leopards don't live in Sumatra

Of all the Panthera cats, the leopard is by far the most adaptable. They have the largest distribution of the Panthera cats, ranging from South Africa all the way to the Russian Far East, but there's one part of the leopards range that's really weird: Indonesia. Java is home to a critically endangered population of leopards that are genetically distinct from leopards in mainland Asia, yet the nearby island of Sumatra has no leopards roaming its jungles at all. In 2017, a paper was published about a possible reason why leopards don't inhabit Sumatra and the reason they gave was competition from other species.

The researchers reconstructed the predator guild of Sumatra's Padang Highlands when leopards lived there, then they created a model on the prey spectrum, how much meat each carnivore ate every day, and the population densities. The guild was then simulated so the scientists could see which situations leopards could've survived in Sumatra. Tigers and humans were not the strongest competitors of leopards in Sumatra, which for some is odd since tigers are leopard killers, but they did find that the exclusions of the dhole, or the clouded leopard, or Asian Golden Cat led to leopards surviving in Sumatra and it also turns out that the small litter sizes of leopards didn't help them out at all either. In the end, the researchers concluded that small litter sizes and competition from dholes, clouded leopards, and Asian Golden Cats caused the fall of the Sumatran leopard. Now you might be able to argue that doesn't make sense since leopards coexist with all those animals in Asia, but you have to remember that Asia is the biggest continent and Sumatra is an island, and islands don't have as many resources as continents do and thus competition on an island will be a bit more intense between competing species.