Four hemagglutinating agents were isolated from 100 cloacal samples collected from migratory water foul during the 1977 hunting season in Michigan. Three of the isolates are paramyxoviruses and they show no reactivity with antisera to Newcastle disease virus. The fourth isolate is an orthomyxovirus, A/Duck/Michigan/77 (Hswl Nav2).

Under experimental conditions two of the paramyxoviruses were recovered from the intestinal tract of chicks, and the third paramyxovirus was recovered from both the respiratory and intestinal tract of chicks. One paramyxovirus was pathogenic for chicks. The type A influenza virus was recovered from both the respiratory and intestinal tracts of chicks and caused subclinical infections