A previous, geographically limited study, has found very little genetic structure in the water rail Rallus aquaticus based on cytochrome oxidase I sequences. Adding samples from Romania, Montenegro, Germany and Spain, we investigated whether the new data confirm the picture of genetic homogeneity or if there is more diverse structure, e.g. due to survival in different Pleistocene refuges. Among 75 studied individuals, there were 12 haplotypes, one of them very common, the others differing in only one or two positions. The high haplotype diversity in Kazakhstan suggested that diversification has been ongoing for a longer time than in the other areas, assuming similar substitution rates across the entire species. Only one rare haplotype was shared between Kazakhstan and another region, specifically Romania. All other rare haplotypes had narrow distributions and probably evolved after the range expansion towards the west. Apparently, gene flow has been restricted in the recent past. The Romanian population was genetically intermediate between Kazakhstan and the western populations. The genetic structure of the populations supported a post-glacial out-of-Central-Asia scenario.

AimsThe purpose of this study was to investigate the culturable aerobic pharyngeal and cloacal bacterial flora of free-living birds, to determine the physiological bacterial microbiota, to identify possible interactions between feeding behaviour and the composition of the pharyngeal and cloacal microflora and to investigate the occurrence of pathogenic bacteria.Methods and ResultsCloacal and pharyngeal swabs of 167 free-living birds, including water rails (Rallus aquaticus), spotted crakes (Porzana porzana), mute swans (Cygnus olor), barn swallows (Hirundo rustica), reed warblers (Acrocephalus scirpaceus) and black cormorants (Phalacrocorax carbo) from Germany, were cultured to determine the prevalence of aerobic bacteria. Statistical analysis of bacterial findings and feeding behaviour was performed. A widespread soil and water bacteria were isolated, which are expected to be present in the habitat and food. However, some potentially avian- and human-pathogenic bacteria, such as Aeromonas hydrophila, Elizabethkingia meningoseptica, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, were also recovered.ConclusionsFree-living birds of the examined species harbour several environmental bacteria, which could be facultative pathogenic.Significance and Impact of the StudyPrevalence of bacteria in healthy free-living birds of the species included in this survey is influenced by environmental and alimentary factors.

Abstract A previous, geographically limited study, has found very little genetic structure in the water rail Rallus aquaticus based on cytochrome oxidase I sequences. Adding samples from Romania, Montenegro, Germany and Spain, we investigated whether the new data confirm the picture of genetic homogeneity or if there is more diverse structure, e.g. due to survival in different Pleistocene refuges. Among 75 studied individuals, there were 12 haplotypes, one of them very common, the others differing in only one or two positions. The high haplotype diversity in Kazakhstan suggested that diversification has been ongoing for a longer time than in the other areas, assuming similar substitution rates across the entire species. Only one rare haplotype was shared between Kazakhstan and another region, specifically Romania. All other rare haplotypes had narrow distributions and probably evolved after the range expansion towards the west. Apparently, gene flow has been restricted in the recent past. The Romanian population was genetically intermediate between Kazakhstan and the western populations. The genetic structure of the populations supported a post-glacial out-of-Central-Asia scenario.