Whilst urbanisation poses a major threat to many species, there is growing evidence to suggest that some species, labelled ‘urban adapters’, are thriving within the urban landscape. Urban landscapes differ drastically from native habitats, where urban adapters are often exposed to a more diverse range of novel food items compared to their rural counterparts, which frequently includes human subsidised resources. Diet is one of the most important factors influencing the gut microbiome, an extremely influential symbiotic community that plays a critical role in many processes affecting host health and fitness, including metabolism, nutrition, immunology and development. Here, using populations of the eastern water dragon in Queensland, Australia, we explore the link between urbanisation, diet and gut microbial changes. We show that city dragons exhibit a more diverse gut microbiome than their rural counterparts, and display microbial signatures of a diet that is richer in plant-material and higher in fat. Elevated levels of the Nitrogen-15 isotope in the blood of city dragons also suggests their diet may be richer in protein. These results highlight that urbanisation can have pronounced effects on the gut microbial communities of wild animals, but we do not yet know the possible repercussions of these microbial changes.

Full article: Littleford‐Colquhoun BL, Weyrich LS, Kent N, Frere CH. City life alters the gut microbiome and stable isotope profiling of the eastern water dragon (Intellagama lesueurii). Mol Ecol. 2019;28:4592–4607. https://doi.org/10.1111/mec.15240