Moult of New Holland Honeyeaters, Phylidonyris novaehollandiae (Aves : Meliphagidae), in Victoria II. Moult of Juveniles

Juvenile New Holland honeyeaters that hatched in autumn commenced a moult in the following spring when about 6 months old. This moult was complete, and the sequence of feather replacement was the same as that of adults; all the primary coverts were replaced. Juveniles that hatched in spring commenced a moult in the summer when 2-6 months old. This moult was usually incomplete; many birds commenced on the second, third or fourth primary, and moult of primaries then proceeded regularly outwards to the tenth primary. Moult of secondaries and rectrices was often incomplete and irregular, and tertiaries were usually all replaced. The primary coverts were rarely replaced. A few spring-hatched juveniles replaced no flight feathers. The later the moult began in spring-hatched juveniles, the more likely it was to start on a more distal primary, and to be less complete in other tracts. Differences in the timing and extent of the moult in different populations and years appeared to be related to food levels. When carbohydrate sources were scarce, the frequency of arrested moult, fault bars and short feathers was higher. Juveniles replaced primaries at a slower rate than adults.