Tracking wintering areas and post-breeding migration of a declining farmland bird – An indispensable basis for successful conservation

• Published in: Global Ecology and Conservation
• Main Authors: Steffen Kämpfer, Helmut Kruckenberg, Heinz Düttmann, Andrea Kölzsch, Frédéric Jiguet, Pierrick Bocher, Thomas Fartmann
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2023
• Subjects: Bird hunting; Eurasian Curlew (Numenius arquata); GPS tracking; Movement ecology; Stopover area; Threatened species; Ecology; QH540-549.5; Eurasian Curlew; Numenius arquata
• Online Access: https://doi.org/10.1016/j.gecco.2023.e02527; https://doaj.org/article/89e0d6c191c1483fa2105e4dd9563ed8

Many farmland birds, such as the Eurasian Curlew (Numenius arquata; here in after Curlew), are in steep decline. So far, decreased reproduction and, hence, an insufficient number of offspring to compensate for adult mortality has been considered the main driver of the recent population collapse. However, despite extensive conservation measures in most breeding areas, there are no signs of a general reversal of the population trend. Accordingly, conservation has to focus on decreasing adult mortality outside the breeding areas as well. For Curlews breeding in NW Germany, ring recoveries suggest that the main wintering areas are the coastlines of western France and southern England. However, such data are often biased in space and time. Here, we used GPS tracking to investigate the wintering areas and post-breeding migration of Curlews of the main German breeding population based on large sample size. Altogether, we tagged 86 adult breeding birds at 23 subareas across a transect of about 250 km (in length) in NW Germany. Curlews started post-breeding migration right after finishing breeding or attempting to breed, which was mainly in mid-June. We identified the coastlines of Great Britain/Ireland, western France and the Netherlands, in particular the Rhine-Meuse-Delta and the Wadden Sea, as the main wintering areas of Curlews breeding in NW Germany. We found a latitudinal structuration of migration, with birds nesting further north using more northerly wintering areas. However, in some cases, wintering areas of birds of the same subpopulation were located more than a thousand kilometres apart from each other. All three main stopover areas identified by our study (German/Dutch Wadden Sea, Dutch Rhine-Meuse-Delta, French Normandy) overlap in large parts with the main wintering areas. Since Curlews spend most of the year outside their breeding areas, and wintering and stopover areas also suffer from rapid environmental change, conservation has to additionally focus on these areas. Nearly one third (29%) of the ...