La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Biometrics and sex ratios of Skylarks Alauda arvensis during migration in southern Italy
Auteurs :	Sergio Scebba, Auteur
Type de document :	Article
Dans :	Ringing & Migration (20(4) November, 2001)
Article en page(s) :	364-370
Résumé :	Biometric data (wing, third primary, tail and tarsus length) were collected from 3,034 Skylarks Alauda arvensis on autumn migration in 1998 and 1999 at Ischitella (Caserta), along the southern Tyrrhenian coastline. There was a clear bimodality in wing, third primary and tail lengths due to sexual size dimorphism. The distributions of biometrics were used with Harding-Cassie plots to separate males from females. On this basis, over the two-year study, between 47.7% (1999) and 56.3% (1998) of birds caught at Ischitella were females and between 31.8% (1998) and 40.7% (1999) were males. The remaining 11.6 to 11.9% had intermediate values of wing, tail and primary length and were not sexed. These sex ratios were very different from those estimated for north European populations, where males predominated in catches.

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