This article was published in the European Journal of Wildlife Research in August 2019.
It deals with the geographical origins of Greylag geese that winter in the Camargue, as isotopic analyses show they more probably come from Central Europe rather than from Scandinavia.
Abstract :
Proper delineation of flyways is a prerequisite for adequate management of migratory birds. The implementation of coordinated international management for greylag goose (Anser anser) is currently underway in Europe for the north-west/south-west (NW/SW) population.
Some uncertainty remained as to whether greylags wintering in Camargue, Southern France, belonged to this
population and bred in Norway, Sweden and Finland, or rather originated from the Central European population, especially since
most neck collar observations were of birds ringed in the Czech Republic.
Stable hydrogen isotope (δ 2 H) analyses of feathers from 147 individuals hunted or trapped during winter in Camargue provide some insight into this question and suggest north-central Europe as a more likely area of origin.
This indicates that greylags wintering along the Mediterranean coast may be largely separate from the birds of the NW/SW European population breeding in Fennoscandia, although some individuals may also come from the Polish or German regions of the NW/SW flyway, since the combined ringing and stable isotope analyses suggest these birds are mostly breeding and moulting in an isotopic area consistent with the Czech Republic, Poland and northern Germany.
Earlier studies show birds wintering in other French regions rather originate from Sweden and Norway. These results should be
considered for the management plan currently being developed for greylag goose in Europe. More generally, they question
whether birds from two distinct populations/flyways should be applied similar or potentially different management plans within a
given country.
Bibliographical reference: Guillemain M., Bacon L., Kardynal K.J., Olivier A., Podhrazsky M., Musil P., Hobson K.A. 2019. Geographic origin of migratory birds based on stable isotope analysis: the case of the greylag goose (Anser anser) wintering in Camargue, southern France. European Journal of Wildlife Research [Internet] [cited 2019 Oct 16]; 65. doi: 10.1007/s10344-019-1304-4
