TURNHOUT C VAN, VOSLAMBER B, WILLEMS F & VAN HOUWELINGEN G (2003) Migration and survival of Greylag Geese Anser anser in the Ooijpolder, the Netherlands. LIMOSA 76 (3): 117-128.

Greylag Geese from the Ooijpolder (Lower Rhine valley) are highly sedentary. Most individuals move within a radius of only a few kilometres from the site where they have been neck-banded (Fig. 1). Two other populations from the southern part of The Netherlands (Scheelhoek, Zeeuws-Vlaanderen) are also sedentary, whereas three populations from the northern part (De Deelen, Oostvaardersplassen, Waterland) are partly migratory and move to southern Spain in winter. This striking difference in migration behaviour may be caused by differences in origin of the populations, being mainly introduced feral geese and wild Scandinavian geese respectively. Capture- recapture analysis (MARK) was used to estimate survival rates. The annual survival probability was 85% for adults and 73% for juveniles (first-year). The annual resighting probability was very high for both groups (99%). There was no obvious difference in survival rate between sedentary and partly migratory populations within the Netherlands. Analysis of bi-monthly resighting data show that resighting rates are high in summer and autumn, both for adults and juveniles (Fig. 2). From February/March onwards, they decrease for adults and are lowest from April to July, as birds are secretive during the breeding and moulting phases. Resighting rates for juveniles decrease from April/May onwards and are, compared to adults, low in summer, when these birds use a larger area and partly move to other sites to moult. Survival rates for adults show little variation in the course of the year (Fig. 2). However, there were no severe winters during the study period. Juvenile survival was lowest in late summer, while in late autumn it is already comparable to adult survival. Apparently, highest juvenile mortality occurs during the last phase of fledging and the relatively long foraging flights in the weeks afterwards. The neck-banding scheme will be continued in forthcoming years: precise estimation of survival rates is important in population modelling, because in a long-lived species like the Greylag Goose, survival has a larger impact on growth rate and population equilibrium than reproduction. We will use population models to assess the factors that determine carrying capacity of the breeding population and to assess the effectivity of population management.

[free pdf] [dutch summary]