JUKEMA J (1998) Migration and winter mortality in a Moorhen Gallinula chloropus population. LIMOSA 71 (1): 1-6.

This paper deals with data from ringing of a small population (c. 20 individuals) of Moorhen living around a farm near a small village in Friesland province, northern part of The Netherlands. Birds were trapped and retrapped since the winter of 1975/76 (total of 553 birds during 21 winters, of which 289 juveniles, 145 adults and 119 "full grown" birds). Body weights of birds trapped in the winters of 1990/91-1995/96 are shown in Fig. 1. Wing length of juveniles was 181.3 mm (N=36, range 165-195), that of adults 186.3 mm (N=57, range 168201).
     Winter mortality in the population studied was not always in agreement with the national trend; this is probably due to local differences in snow cover. Although most Moorhen are resident birds, some birds migrate, especially in severe winters when food (mainly grasses and herbs) is under a snow cover. Annual mortality rate in this small Frisian study-population appears to be similar to these rates in two other populations (birds ringed in Radolfzell and in Heligoland): c. 70%. Common Moorhen Gallinula chloropus

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