No abstract

Predators are an important ecological and evolutionary force shaping prey population dynamics. Ecologists have extensively assessed the lethal effects of invasive predators on prey populations. However, the role of non-lethal effects, such as physiological stress or behavioural responses like dispersal, has been comparatively overlooked and their potential population effects remain obscure. Over the last 23 years, we developed a mark-recapture program for the Audouin’s gull and an intensive carnivore monitoring program to assess how the appearance and invasion of the study site by carnivores affects population dynamics. We evaluate changes in turnover of discrete breeding patches within the colony, age structure and breeding performance. Once carnivores entered the colony, the number of occupied patches increased, indicating a higher patch turnover. Breeders responded by moving to areas less accessible to carnivores. More importantly, the presence of carnivores caused differential (and density-independent) breeding dispersal: experienced, better-performing breeders were more likely to leave the colony than younger breeders. This differential dispersal modified the age structure and reduced the reproductive performance of the population. Our results confirm the importance experience in the study of populations. The role of differential dispersal for animal population dynamics might be more important than previously thought, especially under scenarios of global change.

No abstract

No abstract

No abstract

We assessed habitat use and selection of 16 radio-tracked adult common genets (Genetta genetta) using log-linear models at three different scales (plot, home range and core area) in a Mediterranean area situated in northeast Iberian Peninsula. Genets demonstrate flexibility in habitat use and select habitats using different criteria depending on the scale of analysis, although they show clear selection for habitats formed by forest areas with a tree layer and dense underbrush vegetation cover. Vegetation cover is the most important factor determining habitat selection across all scales. Selections within home range and core area are very similar, with genets showing a preference for pine forest, ravine and holm oak forest over other habitat types (crops, lowland sparse, maquis vegetation and anthropized areas). In resting sites, genets show a strong preference for ravines. Ravine was also the only habitat that is present in the home ranges and core areas of all individuals. Vegetation-associated ravines provide the most cover of all available habitats, and therefore we conclude that these habitats are selected by genets to provide the resources they need. We recommend that management should maintain vegetation cover to preserve the populations of genets.

No abstract

The selection, characteristics and use of 72 resting sites and 3 dens corresponding to 16 adult common genets (Genetta genetta) in a Mediterranean habitat were studied. Over a 3-year period, the common genets each had at least 3–8 resting sites, which were reused with varying frequency. There was a positive correlation between the number of resting sites and the size of the resting home range. They used the resting sites during the day and also at night. The sites were located in thickets and trees. The females preferred thickets, and the males used trees more often than the females. The core areas of individuals revealed a higher number of resting sites than expected in relation to their size. When deciding on where to locate their resting sites, genets selected ravines, seeking the protection and safety that these places offered, with very dense vegetation that was practically inaccessible to any potential predators and thus also sheltering them from human activities. The highest probabilities of resting site presence are found in places near to torrents and away from roads and tracks.