Gunnarsson, G.

virus mallard influenza autumn subtype infection ottenby origin migration study fluenza prevalence feather disease dynamic figure population virus subtypes latorre-margalef isotope recovery sweden pattern band recovery data munster sample species hatch-year condition period body condition hobson factor autumn periods franson direction subtype diversity flint munster vj waldenstrom effect april fouchier waterfowl wassenaar analysis science number diversity influenza virus article body mass ground influenza viruses result wallensten flyway variation assignment outbreak www.plosone.org figure 2 b volume probability influenza virus infection analyses europe issue transmission olsen ottenby bird observatory virus infection distribution hatch-year birds fluenza infection isoscape range water mallard ducks model