2.2. Study design
A cross-sectional study was conducted from March to June 2018, among stakeholders located inside and outside the OD area. The sampling frame was based on databases of hunters and pig farmers provided by the regional authorities. In the case of hunters, a list containing 200 names of the leaders of the local hunting teams has been provided by Regional Association of hunters from Ardèche. A total of 30 hunters were randomly drawn from a list of 200 names: 20 hunters from the OD area and 10 hunters from outside this area. As the participation to interviews was volunteer, if some people drawn refused the interview, the next names on the list were selected.
At the time of the study, the local Animal Health authority could not provide us with an anonymous list of the total of number of outdoor pig farmers in the region (n=81). The selection of farmers was then targeted towards those individuals practicing at least partial outdoor farming in a part of their facilities and therefore, potentially exposed to wild boar incursions (Fig. 1C). Based on this list of persons, one or c) two farmers were sampled by municipality. Selection of the farmers was based on information we could get from other farmers on potential candidates for our survey and their contact details on systematic snowball process the number of 30 farmers. Each candidate was preliminarily contacted by phone to request his/her availability to participate in the survey. The 30 pig farms interviewed were distributed within the OD area (n = 21) and outside (n = 9) on a “first available, first interviewed” basis (Fig. 1C).