La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Migration patterns of Palaearctic Acrocephalus and Sylvia warblers in north-eastern Nigeria.
Auteurs :	Ulf Ottosson, Auteur ; Franz Bairlein, Auteur ; Christian Hjort, Auteur
Type de document :	Article
Dans :	Vogelwarte (41(4) Dezember 2002)
Article en page(s) :	249-262
Langues:	Allemand
Résumé :	In order to gather information on trans-Saharan migration strategies, phenology and energetics the passage of Palaearctic birds was studied in north-eastern Nigeria close to Lake Chad, in spring 1999 and in spring and autumn 2000. The ringing data and biometrics for six Acrocephalus and Sylvia warbler species trapped in sufficient numbers for statistical treatment are analysed with respect to inter-specific and intra-specific (age groups and sex groups) timing of migration, pre-migration fuelling and potential flight ranges. At take-off time in spring most birds carried fat loads that would carry them across the desert and in many cases well into Europe, whereas in autumn the birds arrived after the desert crossing with much lower fat scores. The results of a comparison with data from the same area collected in the late 1960s, when the climate was wetter than nowadays, suggest that the Common Whitethroat (Sylvia communis), a bird of arid habitats, may have adapted to the drier conditions and shifted its winter range southwards.

Lundi , mardi et jeudi de 9h à 12h et de 13h à 17h00 : ouverture au public ...