Barrows Goldeneye (Bucephala islandica) Science Article 4
We studied the timing, duration, and rate of wing molt of male Barrow’s Goldeneye (Bucephala islandica). The mean daily change in primary feather length was 2.6%, which is consistent with rates reported for other waterfowl species. The mean length of the flightless period was 31 days (range: 27-34 days), excluding the pre-shedding interval. Wing molt extended from early July to mid-September. Peak wing molt occurred between 20 July and 23 August.
DEBBIE VAN DE WETERING and FRED COOKE, The Condor 102:228-231