The influence of different aspects of grouse moorland management on non-target bird assemblages

1. Conflict between stakeholders with opposing interests can hamper biodiversity conservation. When conflicts become entrenched, evidence from applied ecology can reveal new ways forward for their management. In particular, where disagreement exists over the efficacy or ethics of management actions, research clarifying the uncertain impacts of management on wildlife can move debates forwards to conciliation.
2. Here, we explore a case-study of entrenched conflict where uncertainty exists over the impacts of multiple management actions: namely, moorlands managed for the shooting of red grouse (willow ptarmigan) Lagopus lagopus in the United Kingdom (UK). Debate over how UK moorlands should be managed is increasingly polarised. We evaluate, for the first time at a regional scale, the relative impacts of two major moorland management practices – predator control and heather burning – on non-target bird species of conservation concern.
3. Birds were surveyed on 18 estates across northern England and south-east Scotland. Sites ranged from intensively managed grouse moors to moorland sites with no management for grouse shooting. We hypothesised that both targeted predator control and burning regimes would enhance ground nesting wader numbers and, as a consequence of this, and of increased grouse numbers, non-target avian predators should also be more abundant on heavily managed sites.
4. There were positive associations between predator control and the abundance of the three most widespread species of ground-nesting wader: strong effects for European golden plover Pluvialis apricaria and Eurasian curlew Numenius arquata and, less strongly, for common snipe Gallinago gallinago. These effects saturated at low levels of predator control. Evidence for effects of burning was much weaker. We found no evidence of enhanced numbers of non-target predators on heavily managed sites.

1. 利益相关方之间因利益对立产生的冲突，会阻碍生物多样性保护工作。当这类冲突根深蒂固时，应用生态学（Applied Ecology）的研究证据可为其管理提供新的解决路径。具体而言，当各方对管理措施的有效性或伦理合理性存在分歧时，阐明管理活动对野生动物的不确定性影响的研究，能够推动相关辩论走向和解。
2. 本研究聚焦一项根深蒂固的冲突案例，该案例中多项管理措施的影响存在不确定性：即英国（UK）境内为开展红松鸡（柳雷鸟，Lagopus lagopus）狩猎而经营的高沼地（moorland）。目前，关于英国高沼地管理方式的争论日益极化。本研究首次在区域尺度上评估了两项主流高沼地管理措施——捕食者管控与石楠焚烧（heather burning）——对具有保护价值的非目标鸟类的相对影响。
3. 研究团队在英格兰北部与苏格兰东南部的18处狩猎庄园内开展了鸟类调查。调查样地涵盖了经营强度极高的红松鸡狩猎高沼地，以及未开展红松鸡狩猎管理的高沼地。我们提出如下假说：针对性捕食者管控与石楠焚烧制度均会提升地面筑巢鸻鹬类（wader）的种群数量；而作为上述效应及红松鸡种群数量增加的结果，经营强度较高的样地内，非目标鸟类捕食者的丰度也应更高。
4. 研究发现，捕食者管控与三种最常见的地面筑巢鸻鹬类的丰度呈正相关：对欧洲金斑鸻（Pluvialis apricaria）和白腰杓鹬（Numenius arquata）的影响较强，对扇尾沙锥（Gallinago gallinago）的影响相对较弱。且这类效应在低强度捕食者管控水平下即达到饱和。石楠焚烧的影响证据则显著薄弱。我们未发现经营强度较高的样地内非目标鸟类捕食者种群数量增加的证据。