Researchers have found that in the Chilean Andes, two predator species — the puma and the culpeo fox — can successfully share a landscape and hunt for food over the same nighttime hours because they are, in essence, ordering from different menus.

«The puma and the culpeo fox are the only top predators on the landscape in the Chilean Andes,» said Professor Marcella Kelly, of the College of Natural Resources and Environment. «And there isn’t a wide range of prey species, in part because the guanacos [closely related to llamas] aren’t typically found in these areas anymore due to over-hunting. With such a simplified ecosystem, we thought we could really nail down how two rival predators interact.»

Kelly worked with Christian Osorio, a doctoral student in the Department of Fish and Wildlife Conservation, and researchers from the Pontifical Catholic University of Chile to chart the locations of and potential interactions between pumas and foxes in central Chile. They focused on three axes of interaction: spatial (where the animals are on the landscape), temporal (the timing of specific activities on a given landscape), and dietary (what each species is eating).

To understand the interplay between pumas and foxes, researchers deployed 50 camera stations across two sites in central Chile, one in the Rio Los Cipreses National Reserve and another on private land where cattle and horses are raised. They also collected scat samples at both locations to analyze the diets of pumas and foxes.

The team’s findings, published in the journal Diversity, showed that while pumas and foxes overlapped significantly where they lived and what time they were active, there was little overlap in what they were eating, with the puma diet consisting primarily of a large hare species introduced from Europe, while the culpeo foxes favored smaller rabbits, rodents, and seeds. The two predator species can successfully share a landscape and hunt for food over the same nighttime hours because they are, in essence, ordering from different menus.

«It is likely that foxes have realized that when they try to hunt hares, they might run into trouble with pumas,» Osorio explained. «If they are hunting smaller mammals, the pumas don’t care, but if the foxes start targeting larger prey, the pumas will react.»

How predator species interact is a crucial question for ecologists trying to understand the dynamics that inform ecosystem balances. And while the puma has been designated a species of least concern, the animal’s populations are declining and continue to be monitored by conservationists.

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Materials provided by Virginia Tech. Original written by David Fleming. Note: Content may be edited for style and length.