Ecología y conservación del gato montés (Felis silvestris silvestris) en un paisaje humanizado

Resum

Human activities affect the behaviour of wildlife species, particularly of carnivores, which play fundamental roles in ecosystems. The growing contact between carnivores and humans urgently calls for increasing the knowledge on natural history of carnivores and studying the effects of human activities on their behaviour. The main aim of the present thesis is to detect behavioural alterations caused by anthropogenic activities in human-modified landscapes on a carnivore species, the European wildcat. Moreover, it pretends to discuss the ecological implications of such changes and propose effective conservation strategies that allow for coexistence between humans and wildcats. The present thesis is divided into six chapters. Chapter 1 addresses the effects of intensive agriculture and landscape configuration on the home range size of wildcats across Europe. Home range size increased in areas with higher presence of intensive agriculture and in homogeneous forests, whereas it decreased when increasing forest edge density. This confirms the preference of wildcats for mosaic-structured landscapes and highlights the potential future risks associated to the current scenario of expanding land intensification. Chapter 2 analyses how the presence and proportion of pastoral fields affect the consumption of different prey items by wildcats, as well as its seasonal variation. Additionally it explores the link between prey abundance and consumption. Arvicola monticola (a field-dwelling large rodent species) was the most consumed item as long as pastoral fields were present, remarking the role of pastoral fields as feeding ground for wildcats. Prey consumption varied seasonally although we found no relationship between inter-annual prey abundance and prey consumption. Chapter 3 evaluates the impacts of human disturbance on wildcat time allocation to different behaviours and hunting success. Wildcats allocated more time to alert and less time to hunting, feeding and moving behaviours in the presence of humans than in undisturbed scenarios, which could add energetic costs for the species. Furthermore, wildcats spent more time hunting in scenarios with more traffic, closer to roads and further from villages. Similarly, they were more vigilant while feeding in the presence of vehicles. Finally, although the effects were not significant, hunting success decreased more in females than in male wildcats in the presence of vehicles which could be related with higher sensitivity to disturbance of females during hunting events. Chapter 4 describes the breeding ecology of wildcats using pastoral landscapes. Litter size at weaning ranged from one to three, with two being the average and most observations occurred during summer. Most auxiliary dens were located inside thick vegetation close to pastoral fields, and human constructions were occasionally used with breeding purposes. Breeding females moved dens frequently and showed high hunting success . Chapter 5 investigates the interspecific interactions occurring between wildcats and foxes. Diurnal encounters between these species are rare, which could result from the two species displaying active avoidance. Foxes showed offensive behaviours whereas wildcats displayed a defensive intimidation strategy, probably in relation to their morphology. Both strategies were equally effective for maintaining the position in feeding grounds. Chapter 6 provides the first description of caching behaviour in wildcats. A wildcat behaved similar to lynx or pumas, and visited a roe deer carcass at least 9 days along a 21 day period, consuming the main muscles and covering it with hair and vegetation. In conclusion wildcats may perceive both negative and positive effects derived from inhabiting human-dominated landscapes. The Cantabrian Mountains provide suitable conditions for wildcats in terms of prey, refuge and breeding opportunities, although wildcats need to deal with the detrimental effects associated to encounters with humans and their activities.