Season as a discriminating factor for faecal metabolomic composition of great tits (Parus major)

The microbiome of wild birds has been associated with health status and risk of disease development, but underlying metabolomic mechanisms are still unknown. Metabolites produced by microbial organisms may affect host metabolic processes and by doing so influence host health. Here we provide for the first time data on the faecal metabolome of wild great tits (Parus major) by analyzing metabolites associations with age, sex, season and body condition. Using untargeted metabolomics, we analyzed faecal samples from 112 great tits that were caught in a deciduous forest fragment in Flanders (Belgium) during late autumn and 19 animals that were re-captured during early spring. In this study, no significant associations between the faecal metabolites and age, sex and body condition were observed. However, season was shown to be a discriminating factor for the metabolomic composition of great tits, suggesting an impact of environmental factors.