Supplementary material from "Increased summer food supply decreases non-breeding movement in black-legged kittiwakes"

• Main Authors: Whelan, Shannon, Hatch, Scott A., Irons, David B., McKnight, Alyson, Elliott, Kyle H.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: The Royal Society 2019
• Subjects: Ecology; FOS Biological sciences; 60801 Animal Behaviour; rissa tridactyla; Alaska
• Online Access: https://dx.doi.org/10.6084/m9.figshare.c.4782561.v1; https://rs.figshare.com/collections/Supplementary_material_from_Increased_summer_food_supply_decreases_non-breeding_movement_in_black-legged_kittiwakes_/4782561/1

Individual condition at one stage of the annual cycle is expected to influence behaviour during subsequent stages, yet experimental evidence of food-mediated carryover 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.