作者: Wolfgang Goymann , Bart Kempenaers , John Wingfield
DOI: 10.1007/S10336-005-0004-X
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摘要: Many internal and environmental factors influence the growth of birds. Here we ask whether reversed sexual dimorphism in classically polyandrous black coucal is reflected differential fledging parameters females males. We also investigate androgen concentrations were higher than males during nestling development, thus, providing a potential mechanism for ‘behavioural masculinization’ female coucals. Furthermore, give detailed description breeding biology this little studied unusual bird species. Black eggs smaller, incubation periods shorter expected that size. In absolute terms coucals grew faster left nest with larger body mass, suggesting are more expensive sex to rear However, relation adult size, slower reached smaller proportion their size upon fledging. ‘Testosterone’ significantly male nestlings, hence not supporting role circulating androgens ontogeny sex-role reversal. To our knowledge, early differences ‘testosterone’ levels represent first evidence such exist nestlings altricial present anecdotal may be related an maturation reproductive organs but males, structural rates.