Comparison of gut microbiota between immigrant and native populations of the Silver-eared Mesia (Leiothrix argentauris) living in mining area

Abstract

The complex gut bacterial communities have a major impact on organismal health. However, knowledge of the effects of habitat change on the gut microbiota of wild birds is limited. In this study, we characterized the gut microbiota of two different subspecies of the Silver-eared Mesia (Leiothrix argentauris), the native subspecies (L. a. rubrogularis) and immigrant subspecies (L. a. vernayi), using 16S rRNA gene high-throughput sequencing. These two subspecies live in a trace metal-contaminated area, and L. a. vernayi was trafficked. They are an excellent system for studying how the gut microbiome of wild animal changes when they move to new habitats. We hypothesized that the immigrant subspecies would develop the same adaptations as the native subspecies in response to habitat changes. The results showed that there were no significant differences in the composition, diversity, or functional metabolism of gut microbiota between native and immigrant subspecies under the combined action of similar influencing factors (the p values of all analyses of variance >0.05). In addition, the composition and functional metabolism of gut microbiota in two subspecies showed adaptation against trace metal damage. Linear discriminant analysis effect size (LEfSe) analysis revealed that Massilia in the intestinal microbiota of immigrant subspecies was significantly higher than that of native subspecies, suggesting that immigrant subspecies suffered habitat change. Finally, we found that these two subspecies living in the mining area had an extremely high proportion of pathogenic bacteria in their gut microbiota (about 90%), much higher than in other species (about 50%) living in wild environment. Our results revealed the adaptation of intestinal microbiota of immigrant Silver-eared Mesias under heavy metals stress, which would provide guidance for biodiversity conservation and pollution management in mining area.

Comparison of fecal microbiota of Little Egret (Egretta garzetta) inhabiting coastal and inland environment

“…Gut microbiota of birds from different habitats with similar a nities can adjust quickly and show convergence after migrating to the same stopover site (Lewis et al, 2017). The gut microbiota of immigrant and native Silver-eared Mesia (Leiothrix argentauris) living in heavymetal-contaminated mining environments did not differ signi cantly in composition, diversity, or function and evolved heavy-metal-contamination damage adaptations with a very high proportion of pathogenic bacteria (Zhou et al, 2023). Interestingly, there is no shortage of studies on birds migrating from the sea to inland, or from inland to the sea, but few articles have been dedicated to investigate the difference of the gut microbiota of the same species that lives in coastal and inland area.…”