The Bobolink (Dolichonyx oryzivorus) is a long-distance migratory grassland songbird whose global population is in long-term decline, largely due to habitat loss and intensification of agricultural practices. To better understand the factors affecting their annual cycle, we used a known-age population of male Bobolinks (n = 121) breeding in agricultural grasslands of Vermont and explored how variation in plumage (extent of yellow in cap) and body morphology (body mass and wing length) explained variation in apparent survival. Bobolink body mass and wing length varied between years 2–5. Bobolink cap size did not change with age. However, none of the 3 morphological characters explained variation in apparent survival. Our results highlight the challenges associated with understanding variation in individual quality relative to age, particularly regarding factors that affect demographic processes in declining species.

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