How are wetlands and biological interactions related to carnivore distributions at high altitude?

Abstract

Determining the geographic range of species is a main objective in ecology and has implications for conservation. Key determinants of carnivore distribution in dry environments are competition and the availability of water. Here, we gathered and mapped the available information on carnivore habitat quality in the high Andes and Puna in the extreme north of Argentina. We investigated four carnivore species: the Andean cat (Leopardus jacobita), the Pampas cat (Leopardus colocolo), the cougar (Puma concolor) and the culpeo fox (Lycalopex culpaeus). We assessed the main determinants of their distribution, testing explicitly for the effects of seasonal and temporal wetlands and biological interactions. We used species distribution models, and created biophysical models using environmental and landscape variables. Then, by including the four species' biophysical models into the model of the focal species, we tested for the importance of biological interactions. Wetlands were most important for the culpeo fox, most likely because it uses aquatic birds as prey. The cougar was the least restricted species in this arid environment, perhaps due to its large home range. In general, environmental variables, distances to wetlands and the annual range of temperature defined species’ distributions better than did biological interactions. Only the distribution of the Andean cat, a specialized species, was influenced by biological interactions with the Pampas cat.