Autumn Moults of Adult and Juvenile Lesser Redpolls in Nottinghamshire, England

Publication Type:Journal Article
Year of Publication:1983
Authors:Boddy, M
Journal:Ornis Scandinavica
Date Published:1983
ISBN Number:00305693
Keywords:Acanthis, Acanthis cabaret, Acanthis flammea, Carduelis, Carduelis cabaret, Carduelis flammea, Fringillidae
Abstract:Moult was studied in a population of Lesser Redpolls Carduelis flammea cabaret breeding in Nottinghamshire, England during 1977-79. A modified linear regression technique for 'date on moult score' was developed to estimate adult moult commencement dates and rates of progress. About 85% of each sex normally commenced moult within separate 3-week periods, females starting 6 d later than males on average. Mean population moult durations (53-60 d in this study) were shown to be at least partially dependent on commencement dates, so that there were considerable annual variations; late breeding seasons resulted in shorter moulting periods. Latitudinal differences in moult parameters suggested by earlier authors could not be confirmed on re-analysis of their data, because of annual variations and incomplete sampling through the moult period. Some breeding birds which had commenced moulting were able to reduce energy requirements, either by slowing feather growth or by suspending their moult temporarily. Juveniles from early broods commenced their autumn moult in the second-half of July and completed by early September, moving away from the moulting areas before the adults. In 1978, many juveniles from later broods had not even commenced moult by mid-September when the study terminated. Juvenile autumn moult duration was about 6-7 weeks.
Short Title:Ornis Scandinavica
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