Migratory waterfowl as flying reservoirs of Yersinia species.

Intestinal contents of tufted ducks and faecal samples from two other species of migratory birds were examined for Yersinia species of organisms. From 296 tufted ducks Yersinia species were isolated from 10 (3·4 per cent), from 223 swans Yersinia species were recovered from eight (3·6 per cent) but none were recovered from the faeces of 121 pintail ducks. Since the isolates differed from each other in their biochemical characteristics and, or, O serotypes, yersinia infection in these migratory waterfowl seemed to be sporadic.