La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Sexual dimorphism of four owl species in South Africa
Auteurs :	Tahla M. Ansara-Ross, Auteur ; Victor Wepener, Auteur ; Gerhard H. Verdoorn, Auteur ; Mathew J. Ross, Auteur
Type de document :	Article
Dans :	Ostrich (79(1) APR 2008)
Article en page(s) :	83-86
Langues:	Anglais
Résumé :	Sexual dimorphism was studied in four South African owl species (African Grass-Owl Tyto capensis, Barn Owl T alba, Marsh Owl Asio capensis and Spotted Eagle-Owl Bubo africanus) by examining specimens of intact owl carcasses found killed by vehicles along a national road in Gauteng province, South Africa. Females were significantly heavier and larger than males for most species. The body mass and length of T capensis, and body mass and tail length of A. capensis, were significantly different, with females being larger than males. Body, wing, tail and tarsus length for T alba males were significantly different to females. For B. africanus, only tarsus length was found to be significantly different among genders. These findings were reiterated further when applying a dimorphism index to the same morphometric measurements. This study contributes to morphometrics distinguishing the sexes of the four southern African owl species, especially T capensis, which has a Vulnerable IUCN status.

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