Behavioural and Distributional Effects of Hunting Disturbance on Waterbirds in Europe: Implications for Refuge Design

1. Based on studies of effects of hunting disturbance on local waterbird distribution and abundance, freedom from such disturbance is concluded to be an important part of waterbird management on nature conservation areas. Measures to mitigate the effects of disturbance from hunting are reviewed. These include complete removal of hunting in refuges, as well as spatial and temporal regulation of hunting activity in reserve areas outwith hunting-free refuges. 2. Disturbance-free refuge design should take account of the ecological requirements of all species using a site and the functional units required to meet all daily activities, especially primary feeding and roosting areas used by waterbirds. Refuge size and shape must ensure birds are free from the effects of external disturbance. The most effective are of regular shape, maximum practicable size, and as a minimum should have a diameter of three times the escape flight distance of the most sensitive species present. 3. Zoning in non-refuge areas can increase local bird numbers by restricting disturbance to regular predictable stimuli to which habituation is more likely. Mobile hunting activity close to roosting and/or feeding areas is more disturbing than hunting from fixed points or where birds are shot moving between such areas. Intermittent hunting is not an effective means of minimizing disturbance, but where implemented rest periods between hunting events should be considered in weeks rather than days. 4. Most studies of mitigation techniques to minimize hunting disturbance have been descriptive and retrospective. Manipulative studies testing specific hypotheses are essential to create a sound scientific base for management. 5. Management of hunting activity should take place within a broader management planning framework that identifies ideal and operational objectives in the management of the site, including feedback monitoring to determine the effectiveness of management prescriptions. 6. We recommend that local site management planning should be integrated internationally, especially in the planning of refuge networks along migration corridors. Management actions in one part of a flyway may affect the ability of areas elsewhere to meet obligations to biodiversity conservation and maintenance of range under international law. In populations that are limited by winter resources, creation of a refuge network may offer a mechanism to enhance population size, but more large scale density dependence s