Dispersal, Survivorship and Demography in the Co-operatively-breeding Bell MinerManorina melanophrys
作者:
ClarkeMichael F.,
HeathcoteCatherine F.,
期刊:
Emu - Austral Ornithology
(Taylor Available online 1990)
卷期:
Volume 90,
issue 1
页码: 15-23
ISSN:0158-4197
年代: 1990
DOI:10.1071/MU9900015
出版商: Taylor&Francis
数据来源: Taylor
摘要:
SummaryClarke, M.F.&Heathcote C.F. (1990). Dispersal, survivorship and demography in the co-operatively-breeding Bell MinerManorina melanophrys. Emu90, 15–23.Females are the dispersing sex in Bell Miners; males tend to be philopatric. The mean age of dispersal (8.0±1.0 months) corresponded closely to the minimum age of first breeding (8.3 months) and may reflect intolerance by females of their sexually mature daughters which may compete for the parental care provided by males. The adult sex ratio was male-biased, probably because of greater dispersal-related mortality suffered by females. Juveniles up to the age of first breeding experienced extremely high mortality (93%). The life expectancy of birds increased dramatically once they reached breeding-age. The number of breeding positions varied little relative to the total number of birds in the social unit. In a social unit of Bell Miners studied over six years there were 6.3 unmated breeding-age birds per breeding vacancy in any month. The level of competitor pressure for breeding positions was more severe for males than females due to the skewed sex-ratio.
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