SEEN - SE European Bird Migration Network
The course of the moult of flight feathers in Yellow-vented Bulbuls (Pycnonotus xanthopygos) caught during autumn season at station Akyatan (S Turkey)
Magdalena Remisiewicz(1) & Özge Keşapl? Can(2)
1)Dept. of Vertebrate Ecology and Zoology Univ. of Gdańsk, al. Legionów 9, 80-441 Gdańsk, Poland
2)Turkish Bird Research Society (KAD), PK. 311 06443 Yenişehir/Ankara, Turkey      

Moult in bulbuls is described in literature only generally; it is known that both adults and immatures undergo a complete moult after the breeding season. Due to lack of clear dimorphism and similar period and range of moult, in all species ageing and sexing is very difficult, if possible at all. During autumn ringing in station Akyatan (36° 36.009´ N  35° 16.575´E,  S Turkey), we described moult pattern in 52 Yellow-vented Bulbuls Pycnonotus xanthopygos, (according to the method of Jenni & Winkler, 1994), caught in period 3.09-5.10.2003. 4 birds were retrapped and progress of their moult was checked. We described advancement of primary, secondary and tertial moult, then moult scores were calculated and analysed. In addition, we noted number of new and old upperwing coverts, allula feathers, rectrices, head and body moult advancement (in % scale), range and colour intensity of the yellow patch on undertail. Primaries were renewed descendently (from inside towards the edge of the wing), secondaries – ascendently (towards the body), tertials – with no clear sequence. In general, two larger groups of birds can be distinguished according to the timing of renewal of both primaries and secondaries, with the dates of moult start 9-10 days apart. Both types of flight feathers were renewed simultaneously (correlation of their moult scores: rS=0.89, p<0.05), however moult of secondaries started only when first few primaries had been already growing. Some birds renewed both types of feathers relatively quickly, while another group kept a similar rate of the primary moult but the renewal of secondaries was retarded. In the timing of tertial moult two groups can be also distinguished. Moult of flight feathers will be analysed against the remaining noted features. The presented results are of preliminary character. Larger sample and data from other parts of the species range could allow to describe the pattern of moult of this species better and possibly to find some clues to ageing and sexing.
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