Estudio de la interacción entre el ganado doméstico y la fauna silvestres como información básica para el control de enfermedades compartidas

The transmission of shared infections at the wildlife – livestock interface has a great impact in a socio-economic and epidemiological context. The study of interactions between both reservoirs becomes necessary to understand the process of transmission of pathogens at the interface, and thus be able to apply effective management measures. In this sense, numerous methodologies exist nowadays to study interactions between animals, each one with specific pros and cons, however, its preferred used will depend on the specific characteristics of each case of study. In this context, the main aim of this PhD Thesis was to study the interactions between wildlife and livestock from a methodological point of view to provide relevant information to apply effective measures to control the transmission of shared pathogens. To address this objective, we first reviewed the different existing methodologies to study interactions between animals (Chapter 1), focusing on their capability to quantify interactions or just give a potential for interactions, and on the characteristics that make the methodology more suitable for the different case of study. This review revealed that methodologies benefit from each other in their ability to quantify interactions or to describe the factors associated with the interactions process. Which methodology to choose will depend on the ecological, physical and social characteristics of each specific case of study. Subsequently, we studied the need to calibrate the information obtained through different methodologies to obtain accurate information on the interaction process (Chapter 2). At this respect, we first calibrated the parameters recorded with proximity loggers with regards different physical factors and a combination of them (Chapter 2.1). Second, we raised the potential use of camera traps set in regular grids as an approach to study interspecific interactions and their spatio-temporal pattern (Chapter 2.2). We observed the need to calibrate the parameters obtained with proximity loggers according to the specific characteristics of each area of study, which can provide a range of possible errors to reach more precise conclusions about the interactions process. We also found a great potential of the information collected through camera traps in regular grids to study the type of interactions between different species and their spatial pattern, although this methodology was not able to describe the frequency of interactions nor the temporal pattern of them. Finally, we carried out the study of interactions in different epidemiological scenarios using different approaches (frequency of interaction, characterization of the spatio-temporal pattern of interactions and dynamic network of interactions) and methodologies, namely GPS technology (Chapter 3) and proximity loggers (Chapter 4). These last chapters were focused on the study of interactions at a fine spatio-temporal resolution on different interfaces, and the characterization of the network of interactions and the role of the different species within it. Results pinpointed that limiting or seasonal resources can act as attractants for both wildlife and livestock, increasing the risk of interactions between groups and the potential for pathogen transmission. Besides, the temporality is also a critical factor in the appearance of interactions. Finally, red deer and fallow deer could be playing a relevant role in the transmission of pathogen to livestock in Mediterranean environments. The results of this Thesis highlight the need to implement the proper methodology to study interactions according to the specific characteristics of the study, the species involved and the pathogen under study. Besides, different methodologies benefit from each other in the combined used of them. The information registered about the interspecific interactions and their spatio-temporal pattern is crucial to develop management measures individualized to each particular scenario and focused on the efficient control of shared pathogens between species.