The effective management of shared pathogens between wild ungulates and livestock requires the understanding of the processes of interaction between them. In this work, we studied the interspecific frequency of interaction (ifreq) and its spatiotemporal pattern between wild and domestic ungulates that coexist in free-ranging farms. For this purpose, 6 red deer, 6 wild boar, 8 Iberian pigs and 3 cattle were monitored using GPS devices during the "montanera" period (the period in which Iberian pigs are maintained in extensive conditions to feed on acorn). The ifreq was quantified for two spatiotemporal windows: 30 m -10 min, for inferring potential direct interactions (short window), and 30 m -12 days for indirect interactions (large window). Secondly, the variation in the ifreq was modelled with regard to 2 temporal (time of the day and week of the year) and 4 environmental factors (distance to water, distance to vegetation cover, Quercus density and distance to feeding points).The interactions at the short window were scarce (N = 13); however, they were very frequent at the large one (N = 37,429), with the red deer as the species with the greatest involvement in the interactions. Models showed that the time of the day and distance to water were the variables that best predicted the ifreq and they were conditioned by differences in the activity pattern of the targeted species. Food resource availability also predicted the ifreq, especially at the short window and between wild species. The results presented here highlight the role that wild ungulates may play in the transmission of pathogens to extensive livestock in general and pigs in particular and show the epidemiological risk of certain areas, periods of time and management practices (for wildlife and livestock) as well as providing useful information in the prevention of the transmission of shared pathogens.

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Background To control the transmission of relevant shared diseases, such as animal tuberculosis (TB) and African swine fever (ASF), it is essential to reduce the risk of interaction between livestock and wild ungulates. In Eastern and Central Europe, the current spread of ASF virus affecting wild boar and domestic pigs (especially those raised outdoors and/or in backyards) has devastated the pig sector in affected regions and is seriously threatening other exporting countries. Here, we evaluated the risk of wildlife-livestock interactions on 45 outdoor pig farms in Spain, the second largest pork producer in the EU and then proposed biosecurity-related actions. An integrated, systematic wildlife risk mitigation protocol based on interviews, questionnaires and field audits was developed and applied on each farm. Results Most of the interaction risk points were associated with water sources (84.2%; 701/832), mainly springs and ponds, which accounted for almost all the specific points with high or very high risk scores. The risk of interaction at feeding points (6.9%; 57/832) and those associated with facilities for livestock and/or game management (8.9%; 74/832) were rated as low and very low risk, respectively. Wild boar were present and hunted on 69% of the farms. Supplementary feeding for wild ungulate species (mainly wild boar) was provided on almost half (48.9%; 22/45) the surveyed farms. Risk mitigation actions were categorised to target water access, waterers, food, other livestock species, grazing, wildlife, and offal disposal. Of the total number of actions (n = 2016), 82.7% were identified as priority actions while 17.3% represented alternative options which were identified less cost-effective. On average, 37.1 (median: 32; range 14–113) action proposals per study farm were made and 2.0 (median: 1; range 0–4) per risk point. The mean estimated cost of implementing the proposed priority actions was 14,780 €/farm (25.7 €/hectare and 799.4 €/risk point). Conclusions This study expands the knowledge of interaction risks between domestic pigs and wild ungulates in outdoor pig farming systems and highlights the importance of considering local risks and management practices when designing and prioritising adapted wildlife risk mitigation and biosecurity actions. This practical and feasible protocol developed for Mediterranean ecosystems is easily transferable to professionals and can be adapted to extensive (outdoor) production or epidemiological systems in other European regions.

BACKGROUND: Fences are one of the most widespread manmade features in nature, constituting an artificial limitation to the movement of wildlife. To date, their effects on wildlife behavior have been understudied but this knowledge is required to design effective management procedures. Using 21 GPS-monitored wild boar, we evaluated the permeability of different types of fences and described temporal patterns and spatial hotspots for crossing events. A fence's permeability was inferred by the crossing success, i.e., the number of times that animals crossed a barrier vs the number of times they did not cross. The vulnerability of fences at watercourses was explored by assessing whether the frequency of crossings was higher around watercourse intersections than expected by chance.RESULTS: Well-maintained big game proof fences were the most effective in reducing successful wild boar crossings; they were, on average, 30% more efficient than livestock type fences. Crossing success was higher for males than females and during the food shortage period than in the food abundance period. The frequency of crossings around watercourses was higher than expected by chance, especially in moderately and well-maintained big game proof type fences.CONCLUSION: While no fence type was 100% wild boar proof, well-maintained big game proof fences substantially constrained the movement of boar. However, they are vulnerable around watercourses. Managing the conflicts in which this species is involved, such as shared infections and agricultural damage, would require fences that are even more effective than the ones analyzed here, ideally in conjunction with other preventive actions.