Abstract
Gut microbiota are increasingly recognized as an integral aspect of host
health, and are influenced by environmental factors, host diet, and
regular physiological stressors such as seasonal host movement
ecologies. Migratory animals experiencing substantial change in diet and
habitat across the annual cycle may have corresponding shifts in
host-associated microbial diversity. Yet, challenges associated with
sample collection from wild animals often inhibit resampling of the same
populations and individuals which in turn decreases the ability to
understand within-individual changes to gut microbiota over time.Using
automated telemetry and radio tags to recapture birds, we examined gut
microbiome structure in the same population and often same individuals
of Kirtland’s Warblers (Setophaga kirtlandii) on their wintering grounds
in The Bahamas and breeding territories in Michigan, USA. The community
composition of gut microbiota varied significantly between locations
with microbial diversity decreasing from The Bahamas to Michigan. We
identified a species-specific core microbial profile that spans multiple
time periods and environments. Our research highlights, at the
individual and population level, that the avian gut microbiome is
dynamic over time and is significantly impacted by changing environments
associated with migration. These results support the need for full
annual cycle monitoring of migratory bird microbiota to improve
understanding of seasonal host movement ecologies and response to
recurrent physiological stressors.