Abstract
Animals generally benefit from their gastrointestinal microbiome, but the factors that influence the composition and dynamics of their microbiota remain poorly understood. Studies of nonmodel host species can illuminate how microbiota and their hosts interact in natural environments. We investigated the role of migratory behaviour in shaping the gut microbiota of free-ranging barn swallows (Hirundo rustica) by studying co-occurring migrant and resident subspecies sampled during the autumn migration at a migratory bottleneck. We found that within-host microbial richness (α-diversity) was similar between migrant and resident microbial communities. In contrast, we found that microbial communities (β-diversity) were significantly different between groups regarding both microbes present and their relative abundances. Compositional differences were found for 36 bacterial genera, with 27 exhibiting greater abundance in migrants and nine exhibiting greater abundance in residents. There was heightened abundance of Mycoplasma spp. and Corynebacterium spp. in migrants, a pattern shared by other studies of migratory species. Screens for key regional pathogens revealed that neither residents nor migrants carried avian influenza viruses and Newcastle disease virus, suggesting that the status of these diseases did not underlie observed differences in microbiome composition. Furthermore, the prevalence and abundance of Salmonella spp., as determined from microbiome data and cultural assays, were both low and similar across the groups. Overall, our results indicate that microbial composition differs between migratory and resident barn swallows, even when they are conspecific and sympatrically occurring. Differences in host origins (breeding sites) may result in microbial community divergence, and varied behaviours throughout the annual cycle (e.g., migration) could further differentiate compositional structure as it relates to functional needs.
| Original language | American English |
|---|---|
| Pages (from-to) | 4706-4720 |
| Number of pages | 15 |
| Journal | Molecular Ecology |
| Volume | 29 |
| Issue number | 23 |
| DOIs | |
| State | Published - Dec 2020 |
Bibliographical note
Funding Information:This research was funded by BSF grant 2015904 to R.N.and W.G. and by NSF grant 1617982 to W.G., R.C.K.B. and P.L.K. S.T. was supported by a doctoral scholarship from the Clore Israel Foundation. We also acknowledge financial support from the Adelina and Massimo Della Pergola Chair of Life Sciences and the Minerva Center for Movement Ecology to R.N., and from the USDA National Institute of Food and Agriculture Hatch project no. ME021908, through the Maine Agricultural & Forest Experiment Station to P.L.K. We thank Yoav Bartan, Motti Charter, Shai Agmon, Dotan Simon, Hedi Ben Eliyahu, Itai Kanter, Netanel Kave, Gabe Rozman, Nikki Thie, Michaela Zinkin, Inbal Rubin, Yoni Vortman and Yosef Kiat for help with fieldwork and logistics, and for species expertise. Thanks to Candace Wang, Hannah Newcombe, Lydia Smith, Katia Lapin, Luba Simanov and Israel Reibstein for help in the laboratory. Thanks to Carla Cicero and Carol Spencer for help with importing samples, and thanks to Sasha Perkarsky for help with making the map figure.
Funding Information:
This research was funded by BSF grant 2015904 to R.N.and W.G. and by NSF grant 1617982 to W.G., R.C.K.B. and P.L.K. S.T. was supported by a doctoral scholarship from the Clore Israel Foundation. We also acknowledge financial support from the Adelina and Massimo Della Pergola Chair of Life Sciences and the Minerva Center for Movement Ecology to R.N., and from the USDA National Institute of Food and Agriculture Hatch project no. ME021908, through the Maine Agricultural & Forest Experiment Station to P.L.K.
Publisher Copyright:
© 2020 John Wiley & Sons Ltd
Keywords
- barn swallow
- microbiome
- migrant
- partial migration
- resident
- stopover bottleneck