AVIS-IBIS

Birds of Indian Subcontinent

Body weights of adult and juvenile Lesser Redpolls in central and southern England

Publication Type:Journal Article
Year of Publication:1984
Authors:Boddy, M
Journal:Ringing & Migration
Volume:5
Issue:2
Date Published:1984
ISBN Number:0307-8698
Keywords:Acanthis, Acanthis cabaret, Acanthis flammea, Carduelis cabaret, Carduelis flammea, Fringillidae, United Kingdom
Abstract:Almost 10000 body weights of adult and first?year Lesser Redpolls were obtained from a variety of sites in southern and central England, including an intensive study in Nottinghamshire during 1977?80. The mean weights of adult males were low (11.2?11.4 g) during May to July; this was the only time of year that adult females were heavier. During late May, 40% of females weighed more than 12.5 g, and the corresponding value in July was 30%. These birds showed evidence of being involved in egg?laying. Males which had commenced moult showed an initial increase of 0.2 g in mean body weight, whilst mean weight of females had declined by 0.75 g at the same stage. Subsequent weight increase during moult was also less for females, and they completed moult at a mean of 11.3 g, compared with 12 g for the males. Juveniles continued weight recession after fledging, with an observed mean loss of 6% whilst they started to feed themselves. Mean body?weight of juveniles just prior to commencing moult was 10.7 g. During active moult they increased by 0.9 g, declining again to a mean of 11.2 g on completion of feather growth. Both adults and juveniles reached their normal maximum body weight in January, and then lost weight in late winter and early spring. In autumn 1977, a period of exceptional Redpoll emigration from Britain, body weights of many individuals from a large flock in Kent were much higher than usual: several birds weighed over 16 g, suggesting pre?migratory fattening. Weight changes in individual body components, as reported by other authors, are used in a discussion of total body weight variations.Almost 10000 body weights of adult and first?year Lesser Redpolls were obtained from a variety of sites in southern and central England, including an intensive study in Nottinghamshire during 1977?80. The mean weights of adult males were low (11.2?11.4 g) during May to July; this was the only time of year that adult females were heavier. During late May, 40% of females weighed more than 12.5 g, and the corresponding value in July was 30%. These birds showed evidence of being involved in egg?laying. Males which had commenced moult showed an initial increase of 0.2 g in mean body weight, whilst mean weight of females had declined by 0.75 g at the same stage. Subsequent weight increase during moult was also less for females, and they completed moult at a mean of 11.3 g, compared with 12 g for the males. Juveniles continued weight recession after fledging, with an observed mean loss of 6% whilst they started to feed themselves. Mean body?weight of juveniles just prior to commencing moult was 10.7 g. During active moult they increased by 0.9 g, declining again to a mean of 11.2 g on completion of feather growth. Both adults and juveniles reached their normal maximum body weight in January, and then lost weight in late winter and early spring. In autumn 1977, a period of exceptional Redpoll emigration from Britain, body weights of many individuals from a large flock in Kent were much higher than usual: several birds weighed over 16 g, suggesting pre?migratory fattening. Weight changes in individual body components, as reported by other authors, are used in a discussion of total body weight variations.
URL:http://www.tandfonline.com/doi/abs/10.1080/03078698.1984.9673836
Short Title:Ringing & Migration
Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith