Meeting Abstract

P3-138    Are snow buntings (Plectrophenax nivalis) using snow surface to load heat in the High Arctic? Lewden, A; O'Connor, RS; Young, KG; Robitaille, F; Love, OP; Elliott, KH; Hargreaves, AL; Berteaux, D; Tam, A; Koutroulides, N; Vézina, F*; Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada ; Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada - Groupe de recherche sur les environnements nordiques BORÉAS, Rimouski, Canada - Centre d'études nordiques, Rimouski, Canada - Centre de la science de la biodiversité du Québec, Rimouski, Canada; Department of Biology, Advanced Facility for Avian Research, Western University, London, ON, Canada; Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada; Department of Integrative Biology, University of Windsor, Windsor, ON, Canada ; Department of Natural Resource Sciences, McGill University, QC, Canada; Department of Biological Sciences, McGill University, Montreal, QC, Canada; Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada - Groupe de recherche sur les environnements nordiques BORÉAS, Rimouski, Canada - Centre d'études nordiques, Rimouski, Canada - Centre de la science de la biodiversité du Québec, Rimouski, Canada; Department of National Defence, 8 Wing Environment, Astra, ON, Canada; Department of National Defence, 8 Wing Environment, Astra, ON, Canada; Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, Rimouski, QC, Canada - Groupe de recherche sur les environnements nordiques BORÉAS, Rimouski, Canada - Centre d'études nordiques, Rimouski, Canada - Centre de la science de la biodiversité du Québec, Rimouski, Canada Francois_Vezina@uqar.ca

Animal thermoregulatory behaviour aims at selecting favourable microhabitats to balance heat loads in thermally heterogenous habitats. Snow buntings (Plectrophenax nivalis) are cold specialized songbirds that arrive on their High-Artic breeding grounds weeks before snowmelt. Our observations at Alert (82°N, Nunavut, Canada) suggest that pre-breeding buntings spend part of their time resting on snow surfaces, despite the availability of dry bare ground. With an albedo close to 1, snow reflets more energy than it absorbs. We thus hypothesized that birds resting on snow surfaces could benefit from higher radiative heat gain than on open bare ground. To test this hypothesis, we deployed 61 3D printed snow buntings at the snow surface and on bare ground. These models were painted to replicate breeding plumage reflectance and were equipped with temperature sensors to measure operative temperatures (T_e) experienced by birds. Our results show that T_e was on average 1,4°C higher (range = -1,0 to 5,9°C) for birds standing on the snow compared to dry bare ground. These data suggest that there is a thermal advantage for these cold specialists to rest on the snow surface in the weeks preceding breeding activities.