Feeding resource partitioning among four sympatric carnivores in the Peneda-Geres National Park (Portugal)

摘要

The Iberian Peninsula comprises two distinct biogeographic areas: a temperate Atlantic Eurosiberian (north) and a Mediterranean (centre and south), and they provide very different biotopes, landscapes and prey for carnivores. One example is an abundance of the wild rabbit Orytolagus cuniculus in the Mediterranean zone, which contrasts with the Eurosiberian zone, where the rabbit is scarce. The feeding resource partitioning among four sympatric predators (red fox Vulpes vulpes, wild cat Felis silvestris, genet Genetta genetta and stone marten Martes foina) was analysed in the Peneda-Geres National Park (north-west Portugal), located in the Eurosiberian region. Data on the spatial distribution of three important prey species (Apodemus sylvaticus, Microtus lusitanicus and Talpa occidentalis) were also collected to investigate their possible relationships with the feeding habits of each predator. Rodents are the staple prey for this guild of carnivores. Predators are able to supplement their diets with one or two secondary prey types: rabbits and arthropods by the largest carnivores (the red fox and the wild cat); insectivores by the small predators (the genet and the stone marten). These results contrast with the characteristic Mediterranean predator-prey features, where rabbits are the main support of carnivore communities. The feeding resource partitioning revealed a complex structure characterized by a dynamic niche differentiation and overlap, according to a seasonal pattern. To explain this pattern of resource exploitation two hypotheses are discussed in the light of the body size of predators and their use of space.