Cloacal and pharyngeal swabs were sampled from 33 Alpine Accentors. A total of 32 specimens were Yersinia positive, with 73% of birds being positive for Y. enterocolitica and 51% for Yersinia spp. A comparison of host characters and environmental conditions showed these to be consistent with the different life strategies of Y. enterocolitica and other Yersinia species. Y. enterocolitica is more successful at colonizing the birds' digestive tracts — the occurrence of Y. enterocolitica was significantly higher in the cloacal than the pharyngeal swabs. The occurrence of Y. enterocolitica was high in summer, especially in the nesting period (July). In juveniles (including nestlings), there was a 100% prevalence of Y. enterocolitica, whereas only two out of nine juveniles were Yersinia spp. positive. There was no significant difference between the occurrence of Y. enterocolitica in anthropogenic and natural habitats, but the occurrence of Yersinia spp. was much greater in the former than in the latter habitats. The presence of the ail gene associated with pathogenic Y. enterocolitica strains was not confirmed in any of the samples examined.