Data from: Variation in age ratio of midcontinent greater white-fronted geese during fall migration at a northern staging area

Annual productivity is an important parameter for the management of waterfowl populations. Fall age ratio (juveniles:total birds) is an index of productivity of the preceding breeding season. However, differences in the timing of migration between family groups and non-breeding birds may bias measures of age ratio estimates. We examined temporal variation in age ratios of midcontinent greater white-fronted geese (Anser albifrons frontalis) from interior and northwest Alaska at a northern autumn staging area near Delta Junction, Alaska. Photographic sampling conducted near Delta Junction resulted in an annual mean age ratio of 0.388 {plus minus} SE 0.004 in 2010 and 0.390 {plus minus} SE 0.001 in 2011. Our study demonstrated temporal variation in age ratios over the duration of the migration period during August and September. We recommend that sampling be conducted for three-day periods at the beginning, middle and end of the migration period to account for temporal variation in migration of family groups.