Energetic cost of tail streamers in the barn swallow (Hirundo rustica)

Abstract:

Different hypotheses stress the importance of natural or sexual selection to explain the evolution and maintenance of long outermost tail feathers in the barn swallow (Hirundo rustica). Since energy costs are pbkp_redicted to arise from tail length manipulation, we measured the daily energy expenditure in three experimental groups (tail-shortened, tail-elongated, and control birds) with the doubly labelled water technique. Though we did not directly measure flight cost, we assumed this to be positively related to daily energy expenditure. Mass independent daily energy expenditure ( day), average daily metabolic rate (ml CO₂/g h), and water flux (ml H₂O/g day) did not show any significant difference among treatments in either sex. Males had higher values than females for the three parameters. Males with short original tail length experienced a higher water flux than originally long-tailed males. Females …

Año de publicación:

1996

Keywords:

Fuente:

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