Food habits of two leopard species, competition, climate change and upper treeline: a way to the decrease of an endangered species?

For carnivore species, spatial avoidance is one of the evolutionary solutions to coexist in an area, especially if food habits overlap and body sizes tend to coincide. We reviewed the diets of two large cats of similar sizes, the endangered snow leopard (Panthera uncia, 16 studies) and the near-threatened common leopard (Panthera pardus, 11 studies), in Asia. These cats share ca 10,000 km(2) of their mountainous range, although snow leopards tend to occur at a significantly higher altitude than common leopards, the former being a cold-adapted species of open habitats, whereas the latter is an ecologically flexible one, with a preference for woodland. The spectrum of prey of common leopards was 2.5 times greater than that of snow leopards, with wild prey being the staple for both species. Livestock rarely contributed much to the diet. When the breadth of trophic niches was compared, overlap ranged from 0.83 (weight categories) to one (main food categories). As these leopard species have approximately the same size and comparable food habits, one can predict that competition will arise when they live in sympatry. On mountains, climate change has been elevating the upper forest limit, where both leopard species occur. This means a habitat increase for common leopards and a substantial habitat reduction for snow leopards, whose range is going to be squeezed between the forest and the barren rocky altitudes, with medium- to long-term undesirable effects on the conservation of this endangered cat.