Culling wildlife hosts to control disease: mountain hares, red grouse and louping ill virus

Abstract

Summary1. Culling wildlife hosts is often implemented as a management technique to control pathogen transmission from wildlife to domestic or other economically important animals. However, culling may have unexpected consequences, can be expensive and may have wider implications for biodiversity and ecosystem functioning. 2. We assess the evidence that culling mountain hares Lepus timidus is an effective and practical way to control louping ill virus in red grouse Lagopus lagopus scoticus. 3. Evidence from the available literature is limited, restricting our ability to reliably assess the effectiveness of culling mountain hares to control ticks, louping ill virus, or increase red grouse densities. Furthermore, the information required to assess the cost-benefit of this management strategy is lacking. The population response of mountain hares to culling is not well understood and the possible effects on their conservation status and the upland ecosystem remain unexplored. 4. We conclude that there is no compelling evidence base to suggest culling mountain hares might increase red grouse densities. 5. Synthesis and applications. Widespread culling of wildlife is not necessarily effective in reducing disease or improving economic returns. The use of wildlife culls for disease control should be proposed only when: (i) the pathogen transmission cycle is fully understood with all host-vector interactions considered; (ii) the response of wildlife populations to culling is known; and (iii) costbenefit analysis shows that increased revenue from reduced disease prevalence exceeds the cost of culling.

Long-term effects of immunocontraception on wild boar fertility, physiology and behaviour

“…Several authors highlighted that culling can affect social behaviour and lead to increased disease transmission whilst fertility control is unlikely to have similar effects (e.g. Smith and Cheeseman 2002;McDonald et al 2008;Killian et al 2009;Harrison et al 2010). In addition, fertility control can induce behavioural changes, such as reproductionrelated long-distance movements, that reduce disease transmission rates (e.g.…”

Environmental impacts of high‐output driven shooting of Red Grouse Lagopus lagopus scotica

“…, Harrison et al . ), so the scientific case for culling Mountain Hares is weak (Werritty et al . ).…”

The effects of acaricide treatment of sheep on red grouseLagopus lagopus scoticatick burdens and productivity in a multi‐host system

“…Estates managed for red grouse in Scotland have cited tick and LIV reductions as one of the reasons for mountain hare culls (Patton et al ., ). A recent review concluded that there was no compelling evidence that hare culls might benefit red grouse when red deer were present (Harrison et al ., ). The current study does not refute this conclusion as it found no relationship to suggest that hare abundance was lower at sites with lower tick burdens or higher rates of grouse breeding success.…”