We studied duckling survival of lesser (Aythya affinis) and greater (A. marila) scaup at Minto Flats, Alaska during 2002–2003. We captured and marked 42 female scaup during the study, and we subsequently monitored survival of 32 scaup broods with 284 ducklings. Daily Survival Rate (DSR) of ducklings varied between years and was positively related to female body condition and duckling age. Estimated duckling survival to 30 days for both species of scaup was 0.24 (95% CI: 0.16 to 0.36) in 2002 and 0.03 (95% CI: 0.00 to 0.19) in 2003. Because we obtained little support for relationships between environmental covariates and duckling survival, we speculated that most of the variation between years could have been related to high rates of predation by gulls (Larus spp.) during 2003. Estimated recruitment of female scaup to 30 days (clutch size * nest survival * duckling survival * 0.5) was 0.30 (SE = 0.19) in 2002 and 0.01 (SE = 0.01) in 2003. Given the low recruitment we observed at Minto Flats and the current population status of scaup, restriction of harvest of adult female scaup could be useful to support scaup populations at Minto Flats.
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Vol. 69 • No. 2