Adult greater white-fronted geese (Anser albifrons frontalis) wintering in southern Oregon and California increased or maintained body weight in autumn, lost weight from autumn through winter, and rapidly increased in weight before spring migration in late April. We documented significant annual differences in body weights for both sexes. We related seasonal changes in body weight to changes in lipid levels, which were lowest (12-13% of wet wt in M and F) in mid-March and highest in late April (24% in F). Greater white-fronted geese maintained lipid levels during winter similar to those reported for large subspecies of Canada geese (Branta canadensis), and greater than those reported for small subspecies of Canada geese and other small species of geese. Protein content of carcasses varied significantly in females; i.e., lowest in early October and highest in late October and late April. Differences among species in patterns of weight change and body composition during winter seem to be related to social organization, body size, food type, and foraging behavior. Females left spring staging areas weighing relatively less than most other species of geese and may have benefited from foraging opportunities on the nesting grounds. J. WILDL. MANAGE. 53(1):80-87 Body weights of geese vary seasonally (Elder 1946, Hanson 1962a), and few quantitative studies of body composition have been conducted (Ankney and MacInnes 1978, Raveling 1979a). Comparisons of among and within year patterns of partitioning of lipids, proteins, and minerals during the annual cycle should increase our understanding of complex interrelationships among foraging ecology, social behavior, and predation, and ultimately contribute to a better understanding of population regulation in geese. We documented body condition of wintering great white-fronted geese that nest in western Alaska and winter primarily in California (Bellrose 1976). We hypothesized that patterns of weight change and body composition of greater white-fronted geese would be similar to large subspecies of Canada geese (McLandress and Raveli g 1981) because of similarities in family s ructure, social organization, diet, and activity patterns (Raveling 1979a, Owen 1980, Johnson and Raveling 1988). Alternatively, patterns of body weight and composition of greater whitefronted geese were predicted to differ from the sympatric-wintering cackling Canada goose (B. c. minima) (Raveling 1979a,b) and Ross' goose (Anser rossi) (M. R. McLandress, Univ. California, Davis, and D. G. Raveling, unpubl. data) because these species differ markedly from I Present address: U.S. Fish and Wildlife Service, Alaska Fish and Wildlife Research Center, 1011 E. Tudor Road, Anchorage, AK 99503. This content downloaded from 207.46.13.151 on Wed, 28 Sep 2016 05:04:12 UTC All use subject to http://about.jstor.org/terms J. Wildl. Manage. 53(1):1989 WHITE-FRONTED GOOSE CONDITION * Ely and Raveling 81 greater white-fronted geese in foraging ecology and social behavior (Johnson and Raveling 1988). Personnel from the U.S. Fish and Wildlife Service (E. J. Collins, R. C. Fields, D. S. Gilmer, J. L. Hainline, J. B. Helvie, E. H. McCollum, and E. J. O'Neill) provided logistic support, field assistance, and encouragement. Field work was accomplished with the help of B. J. Aldrich, S. Castillo, J. Romero, J. Beam, B. Deuel, and W. C. Reinecker. Winema Hunting Lodge Incorporated (Tulelake, Calif.) supplied housing. S. Bartlett, E. Burton, A. Crickmore, J. H. Gammonley, J. Goode, E. Hammond, E. Hoenig, Z. Labinger, S. Loeb, G. Stewart, and J. Weaver assisted with laboratory analyses. M. R. McLandress allowed us to cite unpublished data on Ross' geese and offered assistance and advice with laboratory analysis along with J. S. Sedinger. D. W. Anderson and C. A. Toft reviewed drafts of the manuscript. The California Department of Fish and Game, through the efforts of D. P. Connelly and J. R. LeDonne, made funding available and provided logistic support. The Agricultural Experiment station of the University of California, Davis provided laboratory facilities and financial assistance.