Comparison of the gut fungal communities among Hooded crane (Grus monacha), Greater white-fronted goose (Anser albifrons), and Bean goose (Anser fabalis) at Shengjin Lake, China

The gut microbes regulate a variety of essential functions in avian hosts. Gut microbes are crucial for understanding avian specie's ecological role and potential impact on the ecosystem. A wide range of factors shape the gut microbial diversity and communities in avian hosts, including similarity in genotype and shared evolutionary history, particularly in two closely related host species than distinctly related hosts. In this study, high-throughput sequencing methods were applied to compare and study the similarities and differences in the gut fungal communities of two geese from the same genus Anser, Greater white-fronted goose (Anser albifrons, WG), Bean goose (Anser fabalis, BG) with Hooded crane (Grus monacha, HC) sympatric in overlapping niches at Shengjin lake, China. Our findings supported our hypothesis that the two closely related geese shared similar gut fungal alpha diversity patterns compared to Hooded cranes due to similarity in genotype and evolutionary history. In particular, the fungal community composition in the gut of Greater white-fronted goose showed larger variation relative to the other two species. This result suggested that dietary preferences might regulate the gut fungal communities, as Hooded crane and Bean goose share parallel dietary preferences. The results of the abundance null deviation model showed higher values of null deviation (NDV) in Greater white-fronted goose and Bean goose, indicating that the two closely related goose species might be associated with more robust gut filtering for their fungal community relative to Hooded crane species. The fungal cooccurrence networks were complex, with higher stability in the two congeneric geese species relative to Hooded crane. Moreover, 29 animal fungal putative pathogens were identified with high diversity and relative abundance in the two congeneric geese due to their complex migration patterns compared with Hooded cranes. However, due to niche overlap, direct or indirect association may lead to the dissemination of gut microbes among sympatric avian species. These findings have important implications for ecological research, conservation efforts, and wildlife health management. Moreover, these findings illuminate potential ecological and conservation repercussions and increase our understanding of the complex interactions between avian species and their gut flora.