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Phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata) and White-winged Scoters (Melanitta fusca) on the Pacific coast of North America

November 20, 2012

By quantifying phenology and duration of remigial moult in Surf Scoters (Melanitta perspicillata (L., 1758)) and White-winged Scoters (Melanitta fusca (L., 1758)), we tested whether timing of moult is dictated by temporal optima or constraints. Scoters (n = 3481) were captured during moult in Alaska, British Columbia, and Washington, and remigial emergence dates were determined. We provide evidence for a pre-emergence interval of 7.3 days that occurs after old primaries are shed and before new ones become visible. All age and sex classes of both scoter species exhibited a wide range of emergence dates (Surf Scoters: 26 June to 22 September; White-winged Scoters: 6 July to 21 September) suggestive of a lack of strong temporal optima for remigial moult. For both species, timing of moult was influenced by site, year, age, and sex. Relative to other waterfowl species, scoters have typical remigial growth rates (Surf Scoters: 3.9 mm·day–1; White-winged Scoters: 4.3 mm·day–1) but a long flightless period (34–49 days), in part because their relatively high wing-loading requires a greater proportion of feather regrowth to regain flight. Our data suggest that moulting scoters are not under strong selective pressure to complete moult quickly.

Citation Information

Publication Year 2012
Title Phenology and duration of remigial moult in Surf Scoters (<i>Melanitta perspicillata</i>) and White-winged Scoters (<i>Melanitta fusca</i>) on the Pacific coast of North America
DOI 10.1139/z2012-061
Authors Rian D. Dickson, Daniel Esler, Jerry W. Hupp, E.M. Anderson, J.R. Evenson, J. Barrett
Publication Type Article
Publication Subtype Journal Article
Series Title Canadian Journal of Zoology
Series Number
Index ID 70041067
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center

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