Comparative analysis of intestinal flora community composition and diversity of Anas platyrhynchos and Anser fabalis in the Yellow River Delta

Abstract The Yellow River Delta wetland is a habitat for wintering waterfowl, where mallard ( Anas platyrhynchos ) and tundra bean goose ( Anser fabalis ) are commonly observed. Although the intestinal flora plays a pivotal role in maintaining host health and promoting nutrient absorption, it remains unclear whether the same overwintering habitat and challenging feeding conditions specifically affect the composition and diversity of intestinal flora in both species. Here, high-throughput sequencing was used to compare the intestinal bacterial communities of mallard and tundra bean goose from the same region. There was no significant difference in alpha diversity and beta diversity between the two species. Firmicutes and Proteobacteria were the two predominant phyla, accounting for more than 50.00% of the total. They enhanced the nutrient absorption and metabolic efficiency during overwintering. Catellicoccus was the most dominant genus in the intestinal flora of tundra bean goose, accounting for 33.91%, whereas Clostridium sensu stricto 1 was the most dominant genus in mallard, accounting for 7.34%. This difference is considered to be related to the feeding habits of these two species. No significant differences in the structure and diversity of intestinal bacterial communities were observed between mallard and tundra bean goose, and the similarity of intestinal flora between them was high. This study deepens our understanding of the intestinal flora of two coexisting species with different dietary preferences in the Yellow River Delta. It also lays the foundation for waterfowl disease prevention in this area, carrying significant scientific and practical implications for biodiversity and ecosystem conservation.