Stop-over and Migration Ecology of the Whimbrel: Fall 2009 Season Report

• Main Authors: Smith, F. M., Watts, B. D., Duerr, A. E.
• Format: Text
• Language: unknown
• Published: W&M ScholarWorks 2010
• Subjects: Northwest Territories; Hudson Bay; Canada; Pacific; Hudson; Morrison; Numenius phaeopus; Whimbrel; Alaska
• Online Access: https://scholarworks.wm.edu/ccb_reports/356; https://scholarworks.wm.edu/context/ccb_reports/article/1355/viewcontent/ccbtr_10_01_Smith_Stop_over_and_Migration_Ecology_of_the_Whimbrel_Fall_2009_Season_Report.pdf

The whimbrel (Numenius phaeopus) is a large, Holarctic, highly migratory shorebird. The North American race (N.p. hudsonicus) includes two disjunct breeding populations, both of which winter primarily in Central and South America. The western population breeds in Alaska and the Northwest Territories of Canada (Engelmoer and Roselaar 1998). The eastern population breeds south and west of Hudson Bay in Manitoba and Ontario (Skeel and Mallory 1996, Jehl and Smith 1970). The prevailing thought was that the western population followed a Pacific Coast migration route between breeding and wintering areas in Panama and western South America, and that the Hudson Bay population followed an Atlantic Coast migration route to wintering grounds in Northeast South America (Andres et al. 2009, Skeel and Mallory 1996, Morrison and Ross 1989). Both populations are of high conservation concern due to population declines in recent decades (Bart et al. 2007, Morrison et al. 2006, Watts and Truitt in press). Investigations into the migration routes of whimbrels staging in Virginia have shown a previously unknown link between the eastern and western populations as they stop-over in Virginia (Watts et al. 2008). The primary objective of this project is to examine the stop-over and migration strategies of whimbrels, as they relate to the conservation of the species. A total of four 9.5 gram PTT satellite transmitters were deployed during the fall migration season. Average weight for the whimbrels with transmitters was 527.2 grams, or approximately 200 grams over mean winter (lean) weight. Ten digitally coded glue-on radio transmitters were attached to birds. The cumulative data give us insight into stop-over times for whimbrels as they stage on the Eastern Shore of Virginia before migrating to wintering grounds. Satellite and radio transmittered whimbrels departed the Eastern Shore between 31 August and 20 September 2009. Whimbrels arrived on the Eastern Shore in large numbers as early as early to mid-July due to record low temperatures ...