Department of biology, chemistry and geography
Joël Bêty (Regular member)
Introduction: Among birds, some obstacles encountered during migration, such as deserts or oceans, can act as ecological barriers when refueling opportunities en route are scarce or absent. When facing an ecological barrier, migratory birds may substantially lengthen their migration to circumvent the obstacle or risk undertaking long sustained flights over the inhospitable environment to cross it. The Atlantic Ocean acts as an extensive ecological barrier between the American and the European or African continent. In spring, many nearctic migrants, including the common ringed plover (Charadrius hiaticula), circumvent it by stopping in Iceland, while in autumn, some make longer sustained flights over the ocean. These different migration strategies may be related to the stable wind patterns prevailing over the North Atlantic Ocean. Objectives: The main objective of this project is to assess the effect of wind conditions on the migratory routes used by Bylot Island common ringed plovers to negotiate the North Atlantic Ocean. To do so, we will test whether non-stop Atlantic crossing is possible only for individuals for which wind assistance exceeds a certain threshold. Study sites: Bylot Island is a migratory bird sanctuary located in Nunavut, in the Canadian High Arctic (73’08 N 80’00 W). Data for this project was collected in the southwestern plain of the island. During shorebirds breeding season, this area is covered by wetlands and mesic tundra habitats. Material and methods: I will benefit from geolocation data covering fall and spring migrations of 21 common ringed plovers breeding on Bylot Island and wintering in western Africa. Wind data from the NCEP/NCAR Reanalysis 1 database will be interpolated in time and space to migratory trajectories. This pairing will allow wind assistance calculation along the migratory paths and wind assistance comparison according to the migration strategy used, i.e. the route with or without stopover in Iceland. Expected results: Individuals making the non-stop Atlantic crossing should have a higher wind assistance than would have encountered, on these same routes but at different times, individuals who stopped in Iceland to circumvent the ecological barrier.
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