Small-scale spatial variability in the diet of pampas foxes (Pseudalopex gymnocercus), and human induced changes in prey base

FARIAS, ARIEL; KITTLEIN, MARCELO J.

Ecological Research

Springer

Año: 2008 vol. 23 p. 543 - 550

0912-3814

Predators display functional responses to variation in prey availability that result in dietary distinction at different spatial scales. Such differentiation can be enhanced when human-induced changes in land use increase spatial heterogeneity in prey availability. This has been recorded for canids, but available  information is skewed to regional scales. Further, though human activities have strongly altered neotropical biomes, knowledge about small-scale dietary differentiation of canids come mainly from holartic species. Thus, we quantified variability in the diet of a ubiquitous South American canid species (i.e., the pampas fox, Pseudalopex gymnocercus) over a relatively small area of grasslands in Argentina, comparing its diet at three close sampling sites varying in human disturbance. We found that small-scale dietary differentiation was influenced by human-induced habitat modifications, both directly by local subsidizing of introduced prey (e.g., livestock carrion and hares) and indirectly by altering the availability of native prey. Overall, pampas foxes seemed to be highly flexible in their trophic ecology, being able to cope with marked habitat alterations and likely benefiting from food cross-subsidizing from agricultural landscape to protected grassland relicts. This has implications for management and conservation purposes, and highlights the importance of quantifying variability in foraging behavior of carnivores over small spatial scales.Pseudalopex gymnocercus) over a relatively small area of grasslands in Argentina, comparing its diet at three close sampling sites varying in human disturbance. We found that small-scale dietary differentiation was influenced by human-induced habitat modifications, both directly by local subsidizing of introduced prey (e.g., livestock carrion and hares) and indirectly by altering the availability of native prey. Overall, pampas foxes seemed to be highly flexible in their trophic ecology, being able to cope with marked habitat alterations and likely benefiting from food cross-subsidizing from agricultural landscape to protected grassland relicts. This has implications for management and conservation purposes, and highlights the importance of quantifying variability in foraging behavior of carnivores over small spatial scales.