Female White-winged Scoters (Melanitta fusca) banded at Redberry Lake, Saskatchewan, have an annual survival rate of 78.2 +/- 2.0%. One female captured in July 1985 was at least 18 yr old, a new longevity record for the species.

Department of Zoology University of Guelph Guelph, Ontario N1G 2W1, Canada and Delta Waterfowl and Wetlands Research Station R.R. # 1, Portage la Prairie, Manitoba, Canada West Virginia Co-operative Fish and Wildlife Unit Percwal Hall West Virginia University, P.O. Box 6125 Morgantown, West Virginia 26506-6125 USA 863 University Drwe Saskatoon, Saskatchewan STN OJ8, Canada SOBREVIVENCIA Y LONGEVIDAD DE INDIVIDUOS DE MELANITTA FU$CA ANIDANDO EN SASKATCHEWAN Resumen.--Hembras de Melanitta fusca anilladas en el Lago Redberry, Saskatchewan, mostraron una supervivencia de 78.2 +_ 2.0%. Una hembra capturada en julio de 1985 tenia al menos 18 aftos, lo que constituye un record para la especie. Intensive trapping of female White-winged Scoters (Melanitta fusca degandi) nesting at Redberry Lake, Saskatchewan in 1984 and 1985 has provided additional information on their survival and longevity. A new longevity record was set by a female (847-90183) banded on her nest 12 Jul. 1969, and recaptured on her nest in July 1985. This female was at least 18 yr old because female scoters first breed at 2 yr (Brown 1981) of age and 16 yr had elapsed from the time of first capture. This exceeds Current address: Fish and Wildlife Branch, Department of Natural Resources, P.O. Box 6000, Federicton, New Brunswick E3B 5H1, Canada. TABLE 1. Numbers of breeding female White-winged Scoters in each age class for the populations nesting at Redberry Lake, Saskatchewan, in 1984 and 1985. Age class of breeding female scoters Year <6  6 7 8 9 10 11 15 16 18 1984 47 6 10 8 6 5 2 2 1 -- 1985 -- 42 7 5 4 7 -- -- -- 1  Because there was no intensive banding between 1980 and 1983, birds banded during this time and unbanded birds caught in 1984 were pooled into a <6 year class. Similarly, unbanded birds were pooled with birds banded between 1980 and 1984, in 1985. TABLE 2. Recovery ages of White-winged Scoters banded at locations other than Redberry Lake, Saskatchewan. Years after banding Age at banding < 1 1 2 3 4 5 6 7 8 9 10 11 Adults 14 2 3 0 1 ....... Local, juvenile, hatch year 29 2 6 2 2 2 1 1 1 0 0 1 TABLE 3. Number of adult female White-winged Scoters known to be alive in subsequent years on Redberry Lake, Saskatchewan. Year Number Years after banding banded banded 1 2 3 4 5 6 1966 8 4 3 3 3 3 1 1967 6 3 3 3 3 3 3 1968 2 0 0 0 0 0 0 1969 3 3 1 1 1 1 1 1970 6 3 2 1 1 1 1 1971 9 6 6 6 6 6 6 1972 8 8 8 8 8 6 5 1973 6 3 3 3 3 2 1 1975 31 14 13 12 10 5 2 1976 38 23 21 17 12 3 3 1977 55 32 29 16 9 9 9 1978 51 35 31 19 15 15 15 1979 54 19 12 12 12 12 6 1980 29 11 10 10 10 8 -- 1981 2 0 0 0 0 -- 1982 2 2 2 1 -- 1983 9 7 5 -- 1984 42 7 -- Total 361 180 142 112 91 72 52 all longevity records set by recoveries at Redberry (Table 1) and elsewhere (Table 2). We used data that were collected in 1984 and 1985, from the population of scoters nesting at Redberry Lake, Saskatchewan, to calculate an average age of breeding females (Table 1). The average age of female scoters was 5.6 yr in 1984 and 4.9 yr in 1985, approximately 1 yr older than the previously published average (Brown and Houston 1982). Using the methods outlined by Chapman and Robson (1960) and the data presented in Table 2, we estimate the annual survival rate for adult females 1-16 yr after banding to be 78.2 _+ 2.0% (95% Confidence In- terval) per year. This estimate is higher than the 63.8 _+ 2.8% estimate published previously and is subject to similar biases (Brown and Houston 1982). This estimate should be more accurate than the previous estimate because of the time elapsed between the two studies and the two additional years of intensive banding. Sample sizes for scoters banded elsewhere are too small to allow a survival rate calculation (Table 2). This analysis supports the suggestion that White-winged Scoters are long-lived waterfowl (Brown and Houston 1982). The high annual sur- vival rate is probably an important factor allowing White-winged Scoters to endure the consistently low annual production noted elsewhere (Brown and Brown 1981; Hilden 1964; Koskimies 1955, 1957). TABLE 3. Extended. Years after banding 7 8 9 10 11 12 13 14 15 16 1 1 1 1 3 3 2 1 0 0 0 0 1 1 1 1 1 1 0 0 5 4 3 1 4 4 2 2 1 0 0 0 2 2 2 1 2 2 1 -- 9 7 -- 7 -- 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 1 1 1 0 -- 2 2 0 -- 0 0 -- 0 0 0 1 -- 36 23 12 7 5 5 3 2 1 1 ACKNOWLEDGMENTS Funds for part of this study were provided by the Delta Waterfowl and Wetlands Research Station, Wildlife Mangement Institute, the Office of Migratory Bird Management (contract # iISDI 14-6-009-77-930), Gaylord Memorial Laboratory, and Missouri Agricultural Exper. Station (Project 170 & 183). We gratefully acknowledge the field assistance of M. A. Brown, G. Dobush, K. Rautenstrauch, D. White, and C. Thomas and the staff and students of Delta who assisted in 1984-1985. LITERATURE CITED BROWN, P. W. 1981. Reproductive ecology and productivity of White-winged Scoters. Ph.D. diss. University of Missouri, Columbia. , AND M. A. BROWN. 1981. Nesting biology of the White-winged Scoter. J. Wildl. Manage. 45:38-45. , AND C. S. HOUSTON. 1982. Longevity and age of maturity of White-winged Scoters. J. Field Ornithol. 53:53-54. CHAPMAN, D. G., AND D. S. ROBSON. 1960. The analysis of a catch curve. Biometrics 16:354-368. HILDEN, O. 1964. Ecology of duck populations in the island group of Balassaaret, Gulf of Bothnia. Ann. Zool. Fenn. 1:153-279. KOSKIMIES, J. 1955. Juvenile mortality and population balance in the Velvet Scoter (Melanitta fusca) in maritime conditions. Acta Congr. Int. Ornithol. 11:476-479. ß 1957. Nistortstreue find sterblichkiet bei einem marinen Bestand der Samtente, Melanitta fusca. Vogelwarte 19:46-51. Received 4 Feb. 1987; accepted 22 Jun. 1988.