Increased summer food supply decreases non-breeding movement in black-legged kittiwakes

• Published in: Biology Letters
• Main Authors: Whelan, Shannon, Hatch, Scott A., Irons, David B., McKnight, Alyson, Elliott, Kyle H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 2020
• Subjects: rissa tridactyla; Alaska
• Online Access: http://dx.doi.org/10.1098/rsbl.2019.0725; https://royalsocietypublishing.org/doi/pdf/10.1098/rsbl.2019.0725; https://royalsocietypublishing.org/doi/full-xml/10.1098/rsbl.2019.0725

Individual condition at one stage of the annual cycle is expected to influence behaviour during subsequent stages, yet experimental evidence of food-mediated carry-over effects is scarce. We used a food supplementation experiment to test the effects of food supply during the breeding season on migration phenology and non-breeding behaviour. We provided an unlimited supply of fish to black-legged kittiwakes ( Rissa tridactyla ) during their breeding season on Middleton Island, Alaska, monitored reproductive phenology and breeding success, and used light-level geolocation to observe non-breeding behaviour. Among successful breeders, fed kittiwakes departed the colony earlier than unfed controls. Fed kittiwakes travelled less than controls during the breeding season, contracting their non-breeding range. Our results demonstrate that food supply during the breeding season affects non-breeding phenology, movement and distribution, providing a potential behavioural mechanism underlying observed survival costs of reproduction.