Cumulative effects of environmental conditions and mercury exposure on laying phenology and incubation behaviour

• Main Authors: 3rd World Seabird Conference 2021, Smith, Reyd
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Underline Science Inc. 2021
• Subjects: Animal Science; Ornithology; Arctic; Canada; East Bay; Kyle; Climate change; Somateria mollissima
• Online Access: https://dx.doi.org/10.48448/m4xv-s370; https://underline.io/lecture/34713-cumulative-effects-of-environmental-conditions-and-mercury-exposure-on-laying-phenology-and-incubation-behaviour

Abstract: Wildlife are exposed to many simultaneous stressors, the effects of which are amplified along with increasing human activity globally. In Arctic regions, more severe weather systems, increasing air and ocean temperatures, and exposure to environmental contaminants all represent stressors occurring simultaneously. While seabirds are expected to be at risk of adverse effects from these individual stressors, few studies have researched their combined impacts on breeding behaviour and reproductive success. Therefore, we examined the interactive effects of air temperature, wind speed and mercury (Hg) contamination (via first-laid egg) on laying phenology and incubation behaviour in female common eiders (Somateria mollissima, Mitiq) nesting at Canada's largest Arctic breeding colony (East Bay (Mitivik) Island) from 2016-2019. Exposure to higher pre-breeding air temperatures resulted in females with higher egg Hg concentrations laying earlier than those with lower Hg levels. Furthermore, examination of 190 days of incubation behaviour from 61 eiders across two years showed that nest-level air temperature exposure had the most significant effect on incubation behaviour, with higher air temperatures correlating with more interruptions. Importantly, interactive exposure to higher air temperatures and higher Hg concentrations was related to increased incubation interruptions at a greater effect level than just air temperature alone. Although previous research has shown that warmer spring temperatures may relieve constraints on lower quality females, giving them more time to gain in body condition to successfully lay, our results suggest these females face stronger cumulative costs during incubation in warmer years, especially if they have higher contaminant loads. Our study highlights the potential interactive mechanisms, driven by human-induced environmental changes, that may impact overall individual and colony reproductive success in Arctic seabirds, especially within the context of increasing environmental and predator pressures. Authors: Reyd Smith¹, Saya Albonaimi¹, Holly Hennin², Grant Gilchrist², Jérôme Fort³, Kyle Parkinson¹, Jennifer Provencher², Oliver Love¹ ¹University of Windsor, ²Environment and Climate Change Canada, ³Littoral, Environnement et Sociétés (LIENSs)