Relationships among Breeding, Molting and Wintering Areas of Adult Female Barrow's Goldeneyes (Bucephala islandica) in Eastern North America

Abstract

While the breeding and wintering ranges of the eastern population of Barrow's Goldeneyes (Bucephala islandica) are generally described, molting locations and links among breeding, molting, and wintering areas are unclear, particularly for adult females. Incubating females from the same breeding location (n = 5) were equipped with satellite transmitters in June 2009. Four molting sites were identified over 2 years, spread broadly across Québec: an inlet in Ungava Bay 1,100 km from the breeding area, a lake 100 km south of Ungava Bay (880 km from breeding area), a lake near Hudson Bay (910 km from breeding area) and the mouth of the Rivière aux Outardes River in the St. Lawrence Estuary (165 km from breeding area). The distance between molting females averaged 755 km and two females molted in regions where males were known to molt. Of four birds with consecutive years of molt locations, three showed inter-annual fidelity to within 5 km of the previous molt sites and the fourth molted in sites that were 968 km apart. Females wintered in different locations within the St. Lawrence Estuary and moved widely throughout the area during winter. The south coast of the St. Lawrence Estuary was used during spring and fall staging, and the north coast during winter. There was not strong migratory connectivity among annual cycle stages in eastern adult female Barrow's Goldeneyes, indicating that they should be considered a single management unit that occurs over a broad range throughout the year.