Fencing for wildlife disease control

Fencing is a contentious issue due to its impact on conservation. The Danish government aims to establish a 70 km fence towards the border of Germany and the agricultural ministry of Bulgaria erected 133 km fences along the border with Romania to prevent the spread of African swine fever by wild boar. The Norwegian government recently erected 24 km of fencing as part of combating chronic wasting disease among reindeer. Europe therefore faces a new situation: fencing to limit emerging wildlife diseases. There is, however, surprisingly little scientific literature available on the efficacy of fencing for controlling wildlife disease. Fencing to combat disease include (a) perimeter fencing aiming for containment and reducing likelihood of geographic spread, and (b) hot spot fencing aiming to lower transmission rates within endemic disease areas. Critical limitations of perimeter fencing include: numerous practical and construction details, differences in animal behaviour relative to fences, animal contact along fences, placement relative to natural barriers, human infrastructure that disrupt continuous fencing, and mode of disease transmission including human-aided disease spread. Hot spot fencing is a potentially important way of reducing transmission of diseases once endemic but materials and construction of fences need to be well thought through. A single fence breach does not have the same consequences as for perimeter fencing. Synthesis and applications. Fencing as a tactic to mitigate the spread of disease appears appealing to politicians, but implementation uncertainty is considerable. We fear efforts may be futile unless more attention is paid to both practical and biological detail. There is also an urgent need to build a more evidence-based approach using experience from other sectors.