Flight moult of the Australian honeyeater, Myzantha melanocephala (Latham)

Abstract

Over a period of 3 years 368 M. melanocephala were examined from study areas east and west of the Great Dividing Range in south-eastern Queensland. Moult was under way in 119 of them, and was recorded as a score from 0 to 5 for each of the remiges and rectrices. All populations sampled required about the same period for their members to complete their moult, averaging 153 days for primary feathers and 174 for all flight feathers. The sequence of moult was typically passerine. The estimated average duration for an individual's primary moult is 113 days, complete flight moult requiring 128. Moult occurs between late September and mid- March. It begins later in adult females than in adult males. It also tends to begin about 2 weeks earlier in eastern than western populations, but among eastern birds in 1969 moult began some 26 days later than in 1970 or 1971. A tenuous relation between early rainfall and this late moult is suggested. Immature miners moult in the same sequence as adults but begin by shedding primary 3, 4, or 5, not primary 1. Secondary moult of immatures is even more variable than that of adults, and shows little synchrony with primary moult. Their tail moult is more regular. The period of moult of M. melanocephala is longer than those of the few Australian passerines examined, and much longer than those of passerines from temperate localities. Miners show no cryptic behaviour during moult, and some continue to breed. Thus the prolonged moult is probably adaptive in avoiding interference with other behaviour.