Community Composition
The overarching composition of Kirtland’s Warbler microbiota is
consistent with that of most wild bird surveys to date, with members of
Phyla Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria
comprising the majority of all bacteria detected (Dewar et al. 2014;
Lewis et al. 2016; Grond et al. 2018). However, the relative
abundances of all phyla changed, sometimes dramatically, as the birds
migrated from The Bahamas to Michigan and over time in Michigan.
Variation across the annual cycle may reflect difference in presence or
abundance of environmental bacteria, responses to altered diets that in
turn favor some bacteria over others or vary with host characteristics
and requirements. Below, we consider plausible examples of each.