Survey of Wintering Eurasian Woodcock in Western Europe

Abstract

The Eurasian woodcock (Scolopax rusticola) is a mostly migratory wader (Charadriiformes) that is broadly distributed across the Palearctic. This species winters in or migrates through all European countries and is an important quarry species in many of them. Sustainable management of the species requires information regarding abundance and demographic parameters to be collected regularly. This is a complex task given that different phases of its annual life cycle occur in different countries and, due to the species’ secretive behavior, Eurasian woodcock populations cannot be properly evaluated by common bird-census techniques. In Europe, woodcock hunters from different countries have joined in the Federation of Western Palearctic Woodcock Associations (FANBPO), collecting data on hunting activity that can be used to annually evaluate relative abundance and demographic parameters. To investigate variation in Eurasian woodcock relative abundance during and between hunting seasons, we fitted generalized additive mixed models (GAMMs) to data collected in France, Spain, and Portugal (Franco-Iberian region; 2006–2007 to 2015–2016) to analyze the variation in the number of different Eurasian woodcock seen per hunting trip. For these countries and for Switzerland, Italy, Ireland, and Wales, we also analyzed demographic parameters (the ratios of female:male and juvenile:adult) from bagged birds. In the Franco-Iberian region the relative abundance during the autumn-winter period increased from September to the beginning of December, and remained high thereafter with a slight decrease until the end of February; in the last 10 years, relative abundance has remained stable during autumn migration and winter. The sex ratio remained stable in the Swiss-Franco-Iberian and Swiss-Italian regions, but the former had a higher proportion of females. The age ratio varied among hunting seasons and regions. This research is an example of the effective use of data collected through citizen science that aims to maintain a favorable conservation status of the Eurasian woodcock while allowing a rational use of its populations via sustainable and controlled hunting.