Esteban Gongora

McGill University
Characterization of the thick-billed murre microbiome and its association with sex and diet

Esteban Góngora, Lyle Whyte, Kyle Elliott

Seabirds are often used to monitor contaminant levels in the ocean because they integrate exposure/signals over large areas and bring that signal back to a central location, their colonies, where they can be easily sampled. Individual prey specialization, occurring in many seabirds, should be taken into consideration when using wildlife as bioindicators, given that diet plays an important role on the concentrations and type of contaminants that are accumulated by wildlife. Males and females present variating feeding habits which could also potentially affect the levels of contaminants the animals ingest. As diet can affect the composition of the gut microbiome, it is expected that the bacteria inhabiting the intestines of prey specialists will vary with differential diets. This is also expected to occur between sexes. This study presents the first insights to the gut microbiome of an Arctic seabird, the thick-billed murre (Uria lomvia) from fecal samples using next generation sequencing. Differences in the microbiome in terms of alpha- and beta-diversity between males and females can be explained by the variation in feeding times by sex that occurs at the colony where these birds were studied. Three main types of feces thought to represent different diets were identified, with combinations of them also present for some individuals. These diets were also associated with changes in gut bacterial diversity. Studying the gut microbiome can help us understand the feeding habits of wildlife and how the bacteria in their guts and the animals themselves are affected by different types of contaminants.