1. Senescence has been widely documented in wild vertebrate populations, yet the\ud proximate drivers of age-related declines in breeding success, including allocation\ud trade-offs and links with foraging performance, are poorly understood. For longlived,\ud migratory species, the non-breeding period represents a critical time for\ud investment in self-maintenance and restoration of body condition, which in many\ud species is linked to fitness. However, the relationships between age, non-breeding\ud foraging behaviour and fitness remain largely unexplored.\ud 2. We performed a cross-sectional study, investigating age-related variation in the foraging\ud activity, distribution and diet of an extremely long-lived seabird, the wandering\ud albatross Diomedea exulans, during the non-breeding period. Eighty-two adults aged\ud 8–33 years were tracked with geolocator-immersion loggers, and body feathers were\ud sampled for stable isotope analysis. We tested for variation in metrics of foraging\ud behaviour and linked age-related trends to subsequent reproductive performance.\ud 3. There was an age-related decline in the number of landings (a proxy of foraging effort)\ud during daylight hours, and a decrease in body feather δ\ud 13C values in older males but not\ud females, yet this did not accompany an age-related shift in distributions. Males conducted\ud fewer landings than females, and the sexes showed some spatial segregation,\ud with males foraging further south, likely due to their differential utilization of winds.\ud 4. Although younger (