Trophic plasticity of a tropical seabird revealed through DNA metabarcoding and stable isotope analyses

• Published in: Marine environmental research 2024-07, Vol.199, p.106627, Article 106627
• Main Authors: Marcuk, Vladislav, Piña-Ortiz, Alberto, Castillo-Guerrero, José Alfredo, Masello, Juan F., Bustamante, Paco, Griep, Sven, Quillfeldt, Petra
• Format: Article
• Language: English
• Subjects: Animal biology; Animals; Biodiversity and Ecology; Birds; Birds - physiology; Carbon Isotopes - analysis; Diet; Dietary plasticity; DNA Barcoding, Taxonomic; Environmental Sciences; Feeding strategy; Food and Nutrition; Food Chain; Gulf of California; Life Sciences; Marine ecology; Mexican tropical Pacific; Mexico; Nitrogen Isotopes - analysis; Red-billed tropicbird; Spatio-temporal dietary divergence; Vertebrate Zoology; δ13C; δ15N
• ISSN: 0141-1136; 1879-0291; 1879-0291
• DOI: 10.1016/j.marenvres.2024.106627

DNA metabarcoding and stable isotope analysis have significantly advanced our understanding of marine trophic ecology, aiding systematic research on foraging habits and species conservation. In this study, we employed these methods to analyse faecal and blood samples, respectively, to compare the trophic ecology of two Red-billed Tropicbird (Phaethonaethereus; Linnaeus, 1758) colonies on Mexican islands in the Pacific. Trophic patterns among different breeding stages were also examined at both colonies. Dietary analysis reveals a preference for epipelagic fish, cephalopods, and small crustaceans, with variations between colonies and breeding stages. Isotopic values (δ15N and δ13C) align with DNA metabarcoding results, with wider niches during incubation stages. Differences in diet are linked to environmental conditions and trophic plasticity among breeding stages, influenced by changing physiological requirements and prey availability. Variations in dietary profiles reflect contrasting environmental conditions affecting local prey availability. [Display omitted] •DNA metabarcoding & stable isotopes reveal trophic ecology of Red-billed Tropicbird.•Varying dietary preferences across colonies and breeding stages of tropicbirds.•Spatial diet differences linked to environment & prey availability.•Isotopic niches & prey consumption differ by breeding stage & colony.•Trophic plasticity influenced by physiological changes & prey availability.