La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Are there several species of 'Common' Crosbill Loxia curvirostra in The Netherlands?
Auteurs :	Pim Edelaar, Auteur ; Magnus Robb, Auteur ; Kees van Eerde, Auteur ; Kees Terpstra, Auteur ; Rob Bijlsma, Auteur ; Erik Maassen, Auteur
Type de document :	Article
Dans :	Limosa (77(1) 2004)
Article en page(s) :	31-38
Résumé :	Recent studies have shown that in The Netherlands the Common Crossbill occurs in several 'vocal types'. Vocal types are discrete groups of individuals that are categorised by their flight and excitement calls (Fig. 1). The biological and taxonomic status of these vocal types is currently unknown. In North America, crossbill vocal types differ in biometry, are ecologically specialised, are (at least partly) reproductively isolated, and are therefore most likely separate species. Our preliminary results suggest that the European vocal types are also ecologically specialised (we found significant differences in bill depth; Fig. 2) and reproductivley isolated (we found strong assortative mating), and hence the European vocal types may also represent separate species of crossbill. We discuss and partly refute alternative explanations and highlight which important questions remain to be tackled. Furthermore we call for vocal recordings and information on food of Eurasian crossbills.

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