Reibungsbedingte Abnutzung an einer Handdecke bei Singvögeln.
(von 1994 bis 2006 vergeben)
Federabnutzung, Mauser, Erneuerung, Handschwinge, Armschwinge, Flügeldecken, Handdecke, Alula
Jynx torquilla, Dendrocopos major, Turdus philomelos, Turdus merula, Passer domesticus, Apus apus, Mareca penelope
Wendehals, Buntspecht, Singdrossel, Amsel, Haussperling, Mauersegler, Pfeifente
Selective wear in a songbird wing feather. After a full moult in the course of the year, wing feathers of songbirds and most other bird species normally remain undamaged to a large degree for the rest of the year. This, however, is not true for the innermost upper primary covert in songbirds. Observations were made on 41 full sets of primaries and coverts in House Sparrows Passer domesticus from the author’s feather collection. After moulting, the basal part of the inner vane of the innermost primary covert first loses an adhering series of the downy parts of the barbs. Later, increasing parts of the inner vanes are lost, in some cases up to the rachis. This kind of wear was also found in other songbirds, e.g. Eurasian Blackbird Turdus merula and Song Thrush T. philomelos and in non-songbirds, e.g. Eurasian Wryneck Jynx torquilla and Great Spotted Woodpecker Dendrocopos major. As shown by some provisional experiments both with a dry and a fresh wing of House Sparrows, the outer secondaries and coverts move over the surface of the innermost primary coverts when the wing is folded. During this movement, the outer margin of the great secondary covert No. 1 presumably slides over the basal part of the innermost primary covert thus producing the wear described. The secondary covert itself apparently remains undamaged. The loss of material and web area from the primary covert appears to be of minor value for flying or other wing functions. Presumably it is not under the pressure of natural selection.
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