Hofer, J., F. Korner-Nievergelt, M. Kestenholz, V. Keller & L. Jenni
(* = Kurzbeitrag)
Bewegungsmuster von Reiherenten Aythya fuligula und Tafelenten A. ferina im Winter.
(von 1994 bis 2006 vergeben)
Beringung, Ringfund, Alter, Geschlecht, Bewegungsmuster, Ortswechsel, Wanderung, Zugrichtung, Zugdistanz, Witterung, Temperatur
Aythya fuligula, Aythya ferina
Schweiz, Luzern, Sempachersee
Within-winter movements of Tufted Duck Aythya fuligula and Common Pochard A. ferina. Movements of Tufted Ducks Aythya fuligula and Common Pochards A. ferina within the winter season were analysed with regard to distance, differences in movement patterns between species, sex, age classes, and temperature. We analysed re-encounters of birds ringed and/or re-encountered in Switzerland of which at least two re-encounters (a ringing and recapture/resighting or recovery, or a recapture/resighting and recapture/resighting or recovery) from within the same winter season (December–February) existed. The data consisted of a total of 94 individual Tufted Ducks and 75 Pochards of which 11 and 4 were colour-marked in addition to the normal metal ring.
Pochards covered longer distances than Tufted Ducks. In Pochard, a higher proportion of juvenile males moved more than 50 km than of adult males. For Tufted Duck males the opposite was found. The directions of within-winter movements of Tufted Ducks were more concentrated (towards SW) in females than in males, whereas Pochards showed no such difference between the sexes. Temperature did not influence directions and distances moved.
The within-winter moving activity of both species was generally high, also during mild winters. This indicates that within-winter movements in our data might have been triggered by food depletion or low food availability at Lake Sempach, where most of the individuals were ringed, rather than by cold temperatures. The movement patterns were not identical for all age classes and sexes, which reflects sex- and age-specific wintering strategies.
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