Mapping important roost sites for waders to alleviate human-waterbird conflicts in the Danish Wadden Sea

The coastal zone is subject to growing recreational human activity, which may compromise the suitability of coastal habitats for coastal wildlife. Waders rely extensively on the coastal zone, and they are easily disturbed by human activity when they congregate in large flocks at communal high tide roost sites. To ensure sustainable future development of outdoor recreational activities, emphasis has been given on differentiating between areas prioritized for nature conservation and areas open to human recreation, but only rarely have nature conservation interests been mapped explicitly on a fine spatial scale. The Danish Wadden Sea has recently been identified as a high-conflict area between outdoor activities and waterbirds, and in this paper, we apply 40 years of bird counts covering 12 wader species to build a priority map identifying the most important areas for the future conservation of waders in the region. We outline the most important areas for roosting waders across the Danish Wadden Sea, describe the preferred habitats used for roosting at high tide and assess the persistence of importance of individual areas across 4 decades. Our analysis indicates that importance changes only little even on long temporal scales, demonstrating that the presented priority map will be a useful tool for managers and policy makers when planning the sharing of the Wadden Sea between humans and waders. As such, spatially referenced long-term monitoring data may significantly improve the scientific basis underpinning decision-and policy making, and ensure that nature conservation interests are explicitly accounted for.

Automated summary

The growing recreational human activity in the coastal zone may compromise the suitability of coastal habitats for wildlife. This study uses 40 years of bird counts to identify priority areas for the conservation of waders in the Danish Wadden Sea. The results demonstrate the importance of long-term monitoring data in decision-making and policy planning to ensure the protection of nature conservation interests.