DOI
10.1093/ornithology/ukaf040
Abstract
Diet can be an important health factor that links fitness to an individual’s ecology. The gut microbiome responds to diet changes and plays an important role in host physiology. Dietary interventions are known to impact gut microbiome composition, but long-term effects and to what extent these impacts vary among individuals at different life-history stages are unclear. To address this question, we performed a supplemental feeding experiment by providing live mealworms (Tenebrio molitor) to Sialia sialis (Eastern Bluebird) during the chick-rearing period. We produced 16S metabarcoding data to quantify gut microbiome diversity from fecal samples of adults and nestlings collected during our experimental period, and again 1 year later when the individuals returned to breed at the study site. Food supplementation was associated with shifts in gut microbiome composition for adults, but not early (8-day-old) or late stage (15-day-old) nestlings. In particular, one bacterium in the genus Staphylococcus was more abundant in food-supplemented adults. Nestling gut microbiomes were similar among nest mates, and differed between the sexes during early development, but sex differences disappeared before fledging (nest departure). Microbiome richness was higher in female nestlings, but not related to chick maturity. We did not observe any effects of the previous year’s diet treatment among returning breeders. Humans commonly provide mealworms for S. sialis in order to attract them to their property and to help them achieve nutritional requirements. Our results suggest this practice has limited, short-term effects on gut microbiome diversity that differ among individuals of different life-history stages.
Document Type
Article
Publication Date
9-3-2025
Publisher Statement
Copyright © 2025, © American Ornithological Society 2025. Published by Oxford University Press for the American Ornithological Society
This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
You are not required to obtain permission to reuse this article.
Recommended Citation
Marcella D Baiz, Allison Cornell, Life-history stage-dependent effects of food supplementation on gut microbiome diversity in Sialia sialis (Eastern Bluebird), Ornithology, Volume 143, Issue 1, January 2026, Pages 1–13, https://doi.org/10.1093/ornithology/ukaf040
