It takes guts to grow in the city: the role of the gut microbiome in the welfare of juvenile urban birds
Grantee: Pablo Capilla-Lasheras
Institution: University of Glasgow, United Kingdom
Grant amount: $59,052
Grant type: Challenge grants
Focal species: Blue tits (Cyanistes caeruleus)
Conservation status: Least concern
Disciplines: Physiology, population ecology, animal welfare science, ornithology, animal behavior
Research location: United Kingdom
Publications
Reid, R., et al. (2024). The impact of urbanization on health depends on the health metric, life stage and level of urbanization: a global meta-analysis on avian species. Proceedings of the Royal Society B, 291(2027). https://doi.org/10.1098/rspb.2024.0617
Project summary
Amongst the novel stressors that wildlife face in cities, shifts in diet are prevalent and have negative consequences for welfare, particularly in juveniles. Research clearly shows that juvenile birds in urban habitats have low-quality diets, causing stunted growth and increased early-life mortality. For example, in the UK alone, approximately 30 million blue tits hatch every year in cities, but around 63% of them die as juveniles. This project will study juvenile blue tits and investigate how to improve their welfare in urban areas using an integrative approach that will combine metrics of animal welfare with the study of gut microbiomes. Human and captive animal studies suggest that the gut microbiome composition may contain indicators of an animal’s welfare, but this has received little attention in a wild animal context. This study will combine a physiological welfare indicator (telomere attrition), a behavioral welfare indicator (begging behavior), and other health metrics with a study of juvenile birds’ gut microbiomes to link poor-quality urban diets, gut microbiome composition, and welfare. The project will also test a potential near-term dietary intervention (gut microbiome enrichment) to improve the life experience of juvenile birds growing in urban habitats.
Why we funded this project
Welfare is shaped by, and in turn influences, numerous aspects of an animal’s phenotype. Individual welfare indicators offer only limited insights, but combining indicators across multiple domains is thought to be extremely important for triangulating affective state, or “true” welfare. Because the gut microbiome represents a partially distinct domain, understanding how it relates to welfare could therefore strengthen all of our other indicators when they are used in combination. We were especially interested in this project due to the inclusion of an intervention experiment that could be implemented in the near future. Finally, this project will support an early-career researcher with an interest in wild animal welfare.
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