Questionnaire-Based Assessment of Wild Boar/Domestic Pig Interactions and Implications for Disease Risk Management in Corsica

Abstract

Wild boars and domestic pigs belong to the same species (Sus scrofa). When sympatric populations of wild boars, feral pigs, and domestic pigs share the same environment, interactions between domestic and wild suids (IDWS) are suspected to facilitate the spread and maintenance of several pig pathogens which can impact on public health and pig production. However, information on the nature and factors facilitating those IDWS are rarely described in the literature. In order to understand the occurrence, nature, and the factors facilitating IDWS, a total of 85 semi-structured interviews were implemented face to face among 25 strict farmers, 20 strict hunters, and 40 hunting farmers in the main traditional pig-farming regions of Corsica, where IDWS are suspected to be common and widespread. Different forms of IDWS were described: those linked with sexual attraction of wild boars by domestic sows (including sexual interactions and fights between wild and domestic boars) were most frequently reported (by 61 and 44% of the respondents, respectively) in the autumn months and early winter. Foraging around common food or water was equally frequent (reported by 60% of the respondents) but spread all along the year except in winter. Spatially, IDWS were more frequent in higher altitude pastures were pig herds remain unattended during summer and autumn months with limited human presence. Abandonment of carcasses and carcass offal in the forest were equally frequent and efficient form of IDWS reported by 70% of the respondents. Certain traditional practices already implemented by hunters and farmers had the potential to mitigate IDWS in the local context. This study provided quantitative evidence of the nature of different IDWS in the context of extensive commercial outdoor pig farming in Corsica and identified their spatial and temporal trends. The identification of those trends is useful to target suitable times and locations to develop further ecological investigations of IDWS at a finer scale in order to better understand diseases transmission patterns between populations and promote adapted management strategies.

FaecalEscherichia colias biological indicator of spatial interaction between domestic pigs and wild boar (Sus scrofa) in Corsica

“…Concurrently, the agricultural decline and abandonment of agricultural land in recent decades have led to a notable increase in wild boar populations as evidenced by the approximately 30,000 wild boars hunted annually (ONCFS, ). Similar to other Mediterranean locations, these conditions provide an ideal environment for the interaction between wild and domestic pig populations (Jori, Relun et al., ) and the subsequent maintenance and transmission of pathogens detrimental for both the pig industry (Albina et al., ; Mur et al., ) and human health (Charrier et al., ; Pavio et al., ; Richomme, Boschiroli, Hars, Casabianca, & Ducrot, ). Previous work developed to collect information on interactions between wild and domestic pigs among farmers and hunters indicated a high incidence of direct contacts in extensive pig farms.…”

“…Previous work developed to collect information on interactions between wild and domestic pigs among farmers and hunters indicated a high incidence of direct contacts in extensive pig farms. These mostly resulted from sexual attraction of wild boar by domestic sows in the autumn months, while feeding interactions occurred all year round depending on fruit availability (Jori, Relun et al., ; Trabucco et al., ). Therefore, Corsican pig farming estates provide a well‐characterized environment to validate shared carriage of E. coli strains as biological indicator of infectious contacts between wild boar and domestic pigs under field conditions.…”

“…Our study farm had reported sexual interactions between domestic sows and wild boar, and fights between wild and domestic boar had been observed at least twice during the year preceding the study (Trabucco et al., ). Monitoring of spatial interactions was conducted during 3 months in autumn, which is considered a highly favourable period for sexual driven interactions between wild boar and domestic sows (Jori, Relun et al., ). Indeed, spatial analysis confirmed an overlap of home ranges between both populations under study, even though low GPS success rates kept us from unveiling if those interactions were through direct physical contact or by sharing the same environment.…”

“…Wild boar are generally present in the forested areas of the farm territory (close to the farm settlement or in the mountains) all year round. Although domestic pig–wild boar interactions are more regularly observed during autumn and early winter (Jori, Relun et al., ; Trabucco et al., ), the presence of wild boar close to the animals near the farm settlement remains important all year round (Trabucco et al., ). Wild boar hunting is a well‐established and culturally rooted activity in Corsica (8%–10% of the population practices hunting), with around 30,000 wild boars hunted annually (ONCFS, ).…”

“…For this purpose, we selected an extensive traditional pig farm located in Central Corsica where interactions between domestic pigs and natural populations of wild boar were commonly reported (Jori, Relun et al., ). To assess the occurrence of potential interactions between the two pig populations, telemetry methods were used.…”