Can water table restoration in drained peatlands contribute to improving the population status of Eurasian teal Anas crecca?

Abstract

The Eurasian teal (Anas crecca, hereafter “teal”), a small dabbling duck that breeds across temperate Eurasia and winters farther south, numbers about 670,000 wintering birds in northwest Europe and is an important huntable species. Despite regionally increasing numbers of wintering birds, the European Commission is working to identify key actions to address threats to this species because of its recent classification as "Decreasing" in the EU due to breeding declines in parts of Europe. Teal population dynamics are largely driven by reproductive output rather than by small changes in annual survival. Hence, key actions to increase the extent of highly productive breeding habitats can potentially make a vital contribution to restoring teal to a more favourable population status. Nesting teal thrive on peatlands and acidic wetlands, so peatland restoration can potentially contribute to increased breeding abundance. Results from a literature review and key case studies showed that rewetting and ditch blocking to restore cut-over and drained peatlands for other purposes also attracts nesting teal or significantly increases their local breeding abundance, likely by creating suitable brood rearing habitats that provide abundant invertebrate prey. Results suggest that ditch blocking and associated high shoreline-to-open-water ratios may support higher breeding densities than large blocks of open water. Given the alignment of peatland restoration with EU environmental policies to reduce greenhouse gas emissions, such projects, supported by funding programmes, create favourable conditions for breeding teal by expanding shallow water areas and invertebrate populations. Despite abundant evidence for such effects, further research and especially monitoring are needed to optimise peatland restoration practices for the benefit of teal and other species.