Comparing foraging success of thick-billed murres (Uria lomvia) from two colonies in the Canadian Arctic in response to environmental conditions

• Main Authors: 3rd World Seabird Conference 2021, Eby, Alyssa
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Underline Science Inc. 2021
• Subjects: Ecology; FOS Biological sciences; Ecosystem; Ornithology; Arctic; Canada; Coats Island; Digges; Elliott; Kyle; Nunavut; Climate change; Sea ice; Uria lomvia; uria
• Online Access: https://dx.doi.org/10.48448/5ftp-bf89; https://underline.io/lecture/34864-comparing-foraging-success-of-thick-billed-murres-(uria-lomvia)-from-two-colonies-in-the-canadian-arctic-in-response-to-environmental-conditions

Abstract: Overall, sea ice extent is declining in Arctic systems. However, variability in inter-annual sea ice extent is increasing. Sea ice dynamics greatly influence trophic dynamics in marine systems, where changes in sea ice extent and timing of ice melt can affect the abundance and distribution of fish and invertebrate species. Higher trophic level Arctic breeding species, such as thick-billed murres (Uria lomvia), could be negatively affected by changes in sea ice extent via impacts on foraging behaviour, resulting in greater foraging effort in low ice years. Colony size has also been shown to influence foraging behaviour, where individuals at larger colonies must forage at greater distances as resources surrounding the colony are depleted at a faster rate (Storer-Ashmole's halo hypothesis). As such, the impacts of ice extent on foraging effort are likely to have colony-specific impacts on the energetic profitability of foraging and therefore breeding success. To quantify the impact of changing environmental conditions on the foraging behaviour and payoffs of murres at different sized colonies we deployed GPS units and GPS accelerometers at two colonies in the low Arctic, Coats Island, Nunavut (30 000 breeding pairs; sampled in 2018, and 2019) and Digges Island, Nunavut (400 000 breeding pairs; sampled in 2014, 2015, and 2016). We measured sea ice extent throughout the breeding period and collected blood samples before and after GPS deployments to measure energetic hormones (corticosterone) and energetic metabolites (non-esterified fatty acids, beta-hydroxybutyrate, and triglycerides) as proxies for foraging success of trips. Quantifying the complex impacts of the interaction between colony size and ice extent on foraging success and foraging flexibility will give us predictive insight into which breeding colonies may have a greater capacity of withstanding Arctic climate change. Authors: Alyssa Eby¹, Allison Patterson², Graham Sorenson¹, Thomas Lazarus², Kyle Elliott², H. Grant Gilchrist³, Oliver Love¹ ¹University of Windsor, ²McGill University, ³Environment and Climate Change Canada