Whimbrel populations differ in trans-atlantic pathways and cyclone encounters

• Published in: Scientific Reports
• Main Authors: Watts, Bryan D., Smith, Fletcher M., Hines, Chance, Duval, Laura, Hamilton, Diana J., Keyes, Tim, Paquet, Julie, Pirie-Dominix, Lisa, Rausch, Jennie, Truitt, Barry, Winn, Brad, Woodard, Paul
• Other Authors: U.S. Fish and Wildlife Service, Environment and Climate Change Canada, The National Fish and Wildlife Foundation's Atlantic Flyway Shorebird Initiative, Virginia Coastal Zone Management Program at the Department of Environmental Quality, the New Brunswick Wildlife Trust Fund, The Georgia Department of Natural Resources, Non-game Section, the Environmental Resources Network, a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant, Polar Continental Shelf Program, the Cumulative Impacts Monitoring Program, The Nature Conservancy, Manomet, Inc.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: Multidisciplinary; Hudson Bay; Canada; Hudson; Mackenzie Delta; Whimbrel
• Online Access: http://dx.doi.org/10.1038/s41598-021-92429-z; http://www.nature.com/articles/s41598-021-92429-z.pdf; http://www.nature.com/articles/s41598-021-92429-z

Abstract Each year hundreds of millions of birds cross the Atlantic Ocean during the peak of tropical cyclone activity. The extent and consequences of migrant-storm interactions remain unknown. We tracked whimbrels from two populations (Mackenzie Delta; Hudson Bay) to examine overlap between migration routes and storm activity and both the frequency and consequence of storm encounters. Here we show that Mackenzie Delta and Hudson Bay whimbrels follow different routes across the ocean and experience dramatically different rates of storm encounters. Mackenzie Delta whimbrels departed North America from Atlantic Canada, made long ( $$\bar{x}$$ x ¯ = 5440 ± 120.3 km) nonstop flights far out to sea that took several days ( $$\bar{x}$$ x ¯ = 6.1 ± 0.18) to complete and encountered storms during 3 of 22 crossings. Hudson Bay whimbrels departed North America from the south Atlantic Coast, made shorter ( $$\bar{x}$$ x ¯ = 3643 ± 196.2 km) nonstop flights across the Caribbean Basin that took less time ( $$\bar{x}$$ x ¯ = 4.5 ± 0.29) to complete and encountered storms during 13 of 18 crossings. More than half of Hudson Bay storm encounters resulted in groundings on Caribbean islands. Grounded birds required longer ( $$\bar{x}$$ x ¯ = 30.4 ± 5.32 days) to complete trans-Atlantic crossings and three were lost including 2 to hunters and 1 to a predator. One of the Mackenzie Delta whimbrels was lost at sea while crossing the Intertropical Convergence Zone. Whimbrels use two contrasting strategies to cross the Atlantic including (1) a long nonstop flight around the core of storm activity with a low likelihood of encountering storms but no safety net and (2) a shorter flight through the heart of Hurricane Alley with a high likelihood of encountering storms and a safety network of islands to use in the event of an encounter. Demographic consequences of storm encounters will likely play a role in the ongoing evolution of trans-Atlantic migration pathways as global temperatures continue to rise.