Comparative Analysis of Fecal Bacterial Microbiota of Six Bird Species

The gut microbiota contributes to host health by maintaining homeostasis and improving digestive efficiency. Therefore, identifying gut microbes will shed light on the annual life cycle of animals and in particular those that are threatened or endangered. Nonetheless, the gut microbial composition of the majority of bird species is still unknown. Here, for the first time, 16S rRNA gene sequencing was used to characterize and compare the community composition and diversity of gut microbiotas from six species of birds raised at the Wildlife Conservation Center in Baotou, China: relict gull (Larus relictus; n = 3), muscovy duck (Cairina moschata; n = 3), ruddy shelduck (Tadorna ferruginea; n = 3), demoiselle crane (Anthropoides virgo; n = 4), whooper swan (Cygnus cygnus; n = 3), and black swan (Cygnus atratus; n = 5). A total of 26,616 operational taxonomic units from 21 samples were classified into 32 phyla and 507 genera. Chao1, Shannon diversity, observed species, and Simpson index analysis revealed differences in the community richness and diversity between the different species. Proteobacteria was the dominant bacterial phylum in whooper swan and relict gull, whereas Firmicutes was the dominant bacterial phylum in the other species. At the genus level, 11 dominant genera were detected (Lactobacillus, Psychrobacter, Enterococcus, Carnobacterium, Weissella, Burkholderia, Escherichia/Shigella, Leuconostoc, Buttiauxella, Desemzia, and Staphylococcus). Principal component and cluster analyses revealed that, while the microbial community composition of different individuals of the same species clustered together, the gut microbial composition varied between the bird species. Furthermore, the most abundant bacterial species differed between bird species. Because many avian gut microbes are derived from the diet, the eating habits and natural living environment of birds may be important contributing factors to the observed differences. Short-term changes to the diet and living environment have little effect on the composition of the avian gut microbiota. This study provides a theoretical basis for bird protection, including disease prevention and control.

First detection of Enterocytozoon bieneusi in whooper swans (Cygnus cygnus) in China

Background Enterocytozoon bieneusi is a parasite that infects humans and a wide range of other animals. The large migratory waterfowl, the whooper swan (Cygnus cygnus), travels through many cities during its migration and can spread parasites. Despite receiving increasing attention worldwide, there have been no reports of E. bieneusi infection occurring in C. cygnus. Therefore, this study aims to assess the prevalence and genetic characteristics of E. bieneusi in C. cygnus in Sanmenxia, China. Methods Altogether, 467 fresh fecal samples were collected in the Swan Wetland Park in Sanmenxia, China. Genomic DNA was extracted from fresh fecal samples (n = 467) and E. bieneusi was identified by nested PCR amplification of the internal transcribed spacer (ITS) region. ITS-positive sequences were aligned and phylogenetically analyzed to determine the genotypes of E. bieneusi. Results The overall prevalence of E. bieneusi in C. cygnus was 7.49% (35/467). Sequencing of the 35 positive samples revealed eight known genotypes (EbpA, EbpC, Henan-III, Henan-IV, BEB6, CD9, Peru6 and PtEb IX) and three novel genotypes (CSW1, CSW2 and CSW3). The phylogenetic tree constructed from the ITS sequences showed that seven genotypes (Peru6, EbpA, EbpC, Henan-III, CSW3, Henan-IV and CSW1) clustered within the zoonotic Group 1 while the remaining novel genotype CSW2 clustered within Group 5. Conclusions To our knowledge, this is the first report of E. bieneusi in C. cygnus. Of public health significance, our results suggest that migratory C. cygnus might play an important role in the water-borne transmission of E. bieneusi. Effective strategies will be necessary to control E. bieneusi infection in C. cygnus, other animals and humans.

Waterbird counts on large water bodies: comparing ground and aerial methods during different ice conditions

The paper compares the aerial and ground methods of counting birds in a coastal area during different ice conditions. Ice coverage of waters was the most important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. In ice-free conditions the group of waterbirds with the smallest difference between the two methods (< 6%) contained six species: Greater Scaup, Smew, Mute Swan, Goosander, Common Goldeneye and Tufted Duck; the group with a moderate difference (15%-45%) included another six species: Eurasian Coot, Whooper Swan, Mallard, Eurasian Wigeon, Great Crested Grebe and Common Pochard; while the group with a large difference (> 68%) included five species, all of the genus Anas: Gadwall, Eurasian Teal, Northern Shoveler, Northern Pintail and Garganey. In ice conditions, smaller numbers of most species were counted from the ground, except for Mallard, where the difference between two methods was small (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water without any great impact on the results. When water areas are frozen over, air counts are preferable as the results are more accurate. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then the aerial survey is 40% more economical.

Waterbird counts on large water bodies: comparing ground and aerial methods during different ice conditions

The paper compares the aerial and ground methods of counting birds in a coastal area during different ice conditions. Ice coverage of waters was the most important factor affecting the results of the two methods. When the water was ice-free, more birds were counted from the ground, whereas during ice conditions, higher numbers were obtained from the air. In ice-free conditions the group of waterbirds with the smallest difference between the two methods (< 6%) contained six species: Greater Scaup, Smew, Mute Swan, Goosander, Common Goldeneye and Tufted Duck; the group with a moderate difference (15%-45%) included another six species: Eurasian Coot, Whooper Swan, Mallard, Eurasian Wigeon, Great Crested Grebe and Common Pochard; while the group with a large difference (> 68%) included five species, all of the genus Anas: Gadwall, Eurasian Teal, Northern Shoveler, Northern Pintail and Garganey. In ice conditions, smaller numbers of most species were counted from the ground, except for Mallard, where the difference between two methods was small (7.5%). Under ice-free conditions, both methods can be used interchangeably for the most numerous birds occupying open water without any great impact on the results. When water areas are frozen over, air counts are preferable as the results are more accurate. The cost analysis shows that a survey carried out by volunteer observers (reimbursement of travel expenses only) from the land is 58% cheaper, but if the observers are paid, then the aerial survey is 40% more economical.