Stream acidification alters the gut microbiota of a riparian obligate songbird (Louisiana Waterthrush)

In this study, we investigate the effect of stream acidification on the gut microbial communities of a riparian obligate songbird, the Louisiana Waterthrush (Parkesia motacilla), by sequencing of the bacterial 16S rRNA gene isolated from wild nestling fecal samples. We hypothesized that nestlings reared along acidified streams would harbor distinct gut microbiota compared to conspecifics in circumneutral habitats. Indeed, we found that the gut microbial communities of waterthrush nestlings reared along acidified streams differed significantly from those in circumneutral riparian habitats, exhibiting fewer bacterial OTUs and reduced relative abundances of several bacterial taxa. Additionally, we used previously published molecular diet inventories derived from the same fecal samples to demonstrate that changes in waterthrush nestling diets are correlated with gut microbial community composition.