The annual cycle for whimbrel populations using the Western Atlantic Flyway

• Published in: PLOS ONE
• 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: Paiva, Vitor Hugo Rodrigues, U.S. Fish and Wildlife Service, Environment and Climate Change Canada, National Fish and Wildlife Foundation's Atlantic Flyway Shorebird Initiative, Nature Conservancy, Manomet, Inc., Environmental Resources Network, Natural Sciences and Engineering Research Council of Canada Discovery Grant, New Brunswick Wildlife Trust Fund, Polar Continental Shelf Program, Cumulative Impacts Monitoring Program, Virginia Coastal Zone Management Program at the Department of Environmental Quality, Georgia Department of Natural Resources Non-game Section
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2021
• Subjects: Hudson; Hudson Bay; Mackenzie Delta; Numenius phaeopus; Whimbrel
• Online Access: http://dx.doi.org/10.1371/journal.pone.0260339; https://dx.plos.org/10.1371/journal.pone.0260339

Many long-distance migratory birds use habitats that are scattered across continents and confront hazards throughout the annual cycle that may be population-limiting. Identifying where and when populations spend their time is fundamental to effective management. We tracked 34 adult whimbrels ( Numenius phaeopus ) from two breeding populations (Mackenzie Delta and Hudson Bay) with satellite transmitters to document the structure of their annual cycles. The two populations differed in their use of migratory pathways and their seasonal schedules. Mackenzie Delta whimbrels made long (22,800 km) loop migrations with different autumn and spring routes. Hudson Bay whimbrels made shorter (17,500 km) and more direct migrations along the same route during autumn and spring. The two populations overlap on the winter grounds and within one spring staging area. Mackenzie Delta whimbrels left the breeding ground, arrived on winter grounds, left winter grounds and arrived on spring staging areas earlier compared to whimbrels from Hudson Bay. For both populations, migration speed was significantly higher during spring compared to autumn migration. Faster migration was achieved by having fewer and shorter stopovers en route . We identified five migratory staging areas including four that were used during autumn and two that were used during spring. Whimbrels tracked for multiple years had high (98%) fidelity to staging areas. We documented dozens of locations where birds stopped for short periods along nearly all migration routes. The consistent use of very few staging areas suggests that these areas are integral to the annual cycle of both populations and have high conservation value.