Répartition des canards bagués au Portugal

The outbreak of highly pathogenic avian influenza of the H5N1 virus subtype in Western European countries induced the fear that it could reach Portugal through wild bird migration. Ducks, geese and swans are some of the bird groups with higher prevalence of... More

The outbreak of highly pathogenic avian influenza of the H5N1 virus subtype in Western European countries induced the fear that it could reach Portugal through wild bird migration. Ducks, geese and swans are some of the bird groups with higher prevalence of influenza virus that might be vectors of virus dissemination, considering the existing studies on low pathogenic subtypes that are common in nature (Olsen et al. 2006), and also occur in Portugal (D. Rodrigues et al., unpublished data). Although swans do not occur frequently in Portugal and geese are mostly restricted to Tagus River Estuary Nature Reserve (e.g. Farinha & Costa 1999), ducks are common in Portugal and mostly concentrated on wetlands near the coast (Costa & Guedes 1997), and wintering Aythya duck species are much less numerous than wintering Anas species (e.g. Costa & Guedes 1997). The Portuguese total wintering duck population (Costa & Guedes 1997) is relatively small when compared to the total European population (Sc Less