Origins of juvenile Woodcock (Scolopax rusticola) harvested in Spain inferred from stable hydrogen isotope (δ 2H) analyses of feathers

Woodcock (Scolopax rusticola) are heavily hunted in south-central Europe during the winter and have been the focus of intense management efforts and concern. One of the significant challenges with this and other migratory gamebirds is that they are typically produced in locations other than those where they are primarily harvested. The delineation of origins of harvested Woodcock is important for the identification of appropriate management strategies. Using analysis of stable hydrogen isotope ratios (delta H-2) in feathers of juvenile Woodcock harvested in Spain (2007-2009, n = 802 individuals), we assigned Woodcock origins using a derived Woodcock feather delta H-2 isoscape and four potential isotopic regions covering the breeding range. We also used a continuous probability surface approach that used the forest cover available throughout the range as a constraint on origins. The majority (90 %) of Woodcock captured in Spain were assigned to origins in central-eastern Europe (488 individuals, 60 %), and the Baltic region (237 individuals, 30 %). These results were similar to those previously obtained for Woodcock taken in France (although the relative importance of both eastern Europe and Baltic regions of origin was the opposite to those harvested in Spain). This means that a significant portion of the Spanish and French Woodcock bags can be considered as the same management stock, and thus that management of hunter takes in both countries should be coordinated. Additionally, our results provide further evidence suggesting the need for conservation of forests in Eastern Europe, the southern Baltic, the Ukraine, Belarus, and western Russia.