We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Foraging niche shift maintains breeding parameters of a colonial waterbird during range expansion.
- Authors
Francesiaz, Charlotte; Yohannes, Elizabeth; Besnard, Aurélien; Sadoul, Nicolas; Blanchon, Thomas; Béchet, Arnaud
- Abstract
Relating the effects of foraging niche variation to reproductive dynamics is critical to understand species response to environmental change. We examined foraging niche variations of the slender‐billed gull (Chroicocephalus genei), a nomadic colonial waterbird species during its range expansion along the French Mediterranean coast over a 16‐year period (1998–2013). We investigated whether range expansion was associated with a change in chick diet, breeding success, and chicks body condition. We also examined whether breeding success and chicks body condition were explained by diet and colonial characteristics (number of pairs, laying phenology, habitat, and locality). Diet was characterized using dual‐stable isotopic proxies (δ13C and δ15N) of feather keratin from 331 individuals subsampled from a total of 4,154 chicks ringed and measured at 18 different colonies. δ13C decreased and δ15N increased significantly during range expansion suggesting that chicks were fed from preys of increasing trophic level found in the less salty habitat colonized by the end of the study period. Niche shift occurred without significant change of niche width which did not vary among periods, habitats, or localities either. Breeding success and chick body condition showed no consistent trends over years. Breeding success tended to increase with decreasing δ13C at the colony level while there was no relationship between stable isotope signatures and chick body condition. Overall, our results suggest that even if range expansion is associated with foraging niche shift toward the colonization of less salty and more brackish habitats, the shift had marginal effect on the breeding parameters of the Slender‐billed gull. Niche width appears as an asset of this species, which likely explains its ability to rapidly colonize new locations.
- Subjects
WATER birds; FOOD chains; STABLE isotopes; CHICKS; KERATIN
- Publication
Ecology & Evolution (20457758), 2020, Vol 10, Issue 4, p1988
- ISSN
2045-7758
- Publication type
Article
- DOI
10.1002/ece3.6030