Resource allocation of a deep-diving Arctic seabird, the thick-billed murre (Uria lomvia), in response to sea-ice variation during the chick-rearing period

• Main Authors: 3rd World Seabird Conference 2021, Eby, Alyssa
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Underline Science Inc. 2021
• Subjects: Toxicogenomics; Ecosystem; Environmental Engineering; FOS Environmental engineering; Water Pollution; Arctic; Nunavut; Canada; Elliott; Coats Island; Kyle; Climate change; Sea ice; thick-billed murre; Uria lomvia; uria
• Online Access: https://dx.doi.org/10.48448/emd2-1298; https://underline.io/lecture/34548-resource-allocation-of-a-deep-diving-arctic-seabird,-the-thick-billed-murre-(uria-lomvia),-in-response-to-sea-ice-variation-during-the-chick-rearing-period

Abstract: Presently, inter-annual variability in sea ice dynamics is increasing in Arctic regions. Sea ice dynamics, such as the timing of ice-melt and sea ice extent, highly influence trophic dynamics in marine Arctic systems, leading to changes in the abundance and distribution of fish and invertebrates. Thick-billed murres (Uria lomvia) - a pursuit diving seabird that preys upon pelagic fish, benthic fish, and invertebrates - are thus expected to be negatively impacted by shifts in marine Arctic community structure. As such foraging behaviour, including the decision to balance self-feeding and chick-provisioning, will be influenced by environmental conditions, and mediated by either adult or chick body condition. In a low ice year, associated with reduced food availability, adults may choose to maximize self-feeding to maintain adult condition, while reducing chick provisioning at the cost of chick condition. Alternatively, adults may maintain or increase chick-provisioning to maximize chick condition, while reducing self-feeding at the cost of adult condition. To investigate the impact of environmental conditions on resource allocation decisions in this system we fitted adult murres with GPS accelerometers during the incubation and chick-rearing periods at Coats Island, Nunavut, Canada in 2018 and 2019. To assess the success of foraging trips for adult energetic condition we blood sampled murres before/after GPS deployments to measure energetic hormones (corticosterone), metabolites (non-esterified fatty acids, beta-hydroxybutyrate, and triglycerides), and stable isotopes (δ13C and δ15N). To assess the success of foraging trips for chick energetic condition, we conducted feeding watches to identify prey types and chick-provisioning rates. By determining how variation in environmental conditions impacts resource allocation decisions, we can predict how breeding success and ultimately fitness will be impacted in rapidly changing Arctic ecosystems. Authors: Alyssa Eby¹, Allison Patterson², Kyle Elliott², H. Grant Gilchrist³, Oliver Love¹ ¹University of Windsor, ²McGill University, ³Environment and Climate Change Canada