Ardea
Official journal of the Netherlands Ornithologists' Union

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Doude van Troostwijk W.J. (1974) Ringing data on White-fronted Geese Anser a. albifrons in The Netherlands, 1953-1968. ARDEA 62 (1-2): 98-110
l. From 1953/1954 to 1967/1968 inclusive, 9,275 White-fronted Geese were caught and ringed in The Netherlands, giving about 1,400 recoveries. 2. Fluctuations in the numbers wintering in The Netherlands do not show any upward or downward trend. 3. From the catches for ringing research it could be calculated that the mean percentage of first-year birds is 39,2. 4. The mean annual mortality for geese over one year old was estimated to be 30.9%. White-fronted Geese in their first winter have the same survival chance as adults. 5. On average 40% of the population consists of geese of three years and older. One pair of mature birds thus raises two full-grown young. 6. The sex-ratio of adults is l.00 ? : l.05 ?, and of first-year birds l.00 : l.09, these figures do not differ from a ratio of l.00 : l.00. 7. The average body weights prove to be very stable, even in very hard winters. 8. The geographical distribution and the migration route are given in Figures 3 and 4. 9. Mean coordinates of recovery in winter show a tendency to concentrate on more westerly situated areas. This indicates the growing importance of The Netherlands, Belgium and Great Britain as wintering areas. It is thought that different wintering areas may be of different significance for the various age groups. 10. Emphasis should be laid upon an adequate network of sanctuaries along the coast and estuaries of Western Europe. Censuses and ringing research should be continued to ensure up-to-date information for an adequate management.


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