La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Song flight performance in the Skylark Alauda arvensis
Auteurs :	A. Hedenstrom, Auteur
Type de document :	Article
Dans :	Journal of Avian Biology (26(4) DEC 1995)
Article en page(s) :	337-342
Langues:	Anglais
Résumé :	Song flight in birds serves as a signal involved in mate choice and territoriality. In the Skylark Alauda arvensis the song flight is a noticeable feature during the breeding season. Single song flights sometimes lasted for more than 30 min, but the average duration was about 4 min. In this study I dissect the flight performance during the three phases of Skylark song flight: climbing, level and descending flight. During climb, the Skylark exhibits a power expenditure well below the estimated maximum capacity. The average climb speed was 0.98 m s(-1). During level flight, which makes up the longest part of the whole song flight, the larks seem to minimize the energy cost by flying at the minimum power speed V-mp if the wind allows. This was evident from the occurrence of circling and turning flight in calm conditions and more stationary wind hovering at wind speeds above V-mp. Finally, descent is most often by parachuting at a mean sinking speed of 1.5 m s(-1); diving with folded wings gave a mean sinking speed of 8.4 m s(-1); flapping descent resulted in a mean sinking speed of 1.6 m s(-1).

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