La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Three-bird flights in migratory geese - a review
Auteurs :	H. Boyd, Auteur ; A. D. Fox, Auteur
Type de document :	Article
Dans :	Wildfowl (54 2003)
Article en page(s) :	143-161
Langues:	Anglais
Résumé :	Three-bird flights (3BF) have been reported amongst seven species of geese: 12 populations of Branta and seven of Anser. The phenomenon has been recorded from mid-winter to the start of incubation, being most frequent and intense during the period of first egg laying. As previously reported, pursuit flights (often involving more than three geese) in wintering and staging areas seem not to be of crucial importance. Pursuits at breeding places offer opportunities for males to achieve forced extra-pair copulations (FEPC) with paired sexually-mature females. This may represent both a primary strategy for solitary mature males and a secondary strategy for paired males with incubating females, which can secure extra-pair copulations (EPC) without cost to their primary reproductive investment. The authors suggest also that 3BF enable females to assess the relative strength and condition of the males to whom they are attached and of the males seeking to usurp them. This may allow females to make choices about accepting EPC from attacking males to contribute to the paternal composition of their reproductive effort. It also seems likely that 3BF offer females not yet paired an opportunity to choose between potential partners prior to the establishment of longterm monogamous bonds.

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