Habitat related differences in age structure and reproductive parameters of red foxes

We studied the age-structure and the reproductive parameters in two samples of red foxesVulpes vulpes (Linnaeus, 1758) from two contiguous areas in the Ebro valley (NE Spain) differing in the level of deliberate culling and in the habitat quality. Percent of juvenile foxes in the semiarid steppe (under higher persecution) was lower (53%) than in the irrigated highly productive “vegas” (67%). Conversely, foxes in the “vegas” (more favourable habitat) had a larger litter size (3.9 ± 0.23 cubs per female) and a higher amount of barren vixens (19.3%) than in the steppe (3.3 ± 0.12 cubs per female, and 1.7% of barren vixens). In this study, migration due to juvenile dispersal does not hide the effects of the habitat on fox population dynamics, despite the proximity between both areas. The results are discussed in relation to previous studies on red fox population dynamics.