RESEARCH ARTICLE Foraging Strategies of Laysan Albatross Inferred from Stable Isotopes: Implications for Association with Fisheries

Fatal entanglement in fishing gear is the leading cause of population decline for albatross globally, a consequence of attraction to bait and fishery discards of commercial fishing oper-ations. We investigated foraging strategies of Laysan albatross (Phoebastria immutabilis), as inferred from nitrogen and carbon isotope values of primary feathers, to determine breed-ing-related, seasonal, and historic factors that may affect the likelihood of association with Alaskan or Hawaiian longline fisheries. Feather samples were collected from live birds mon-itored for breeding status and breeding success on Midway Atoll in the northwestern Hawai-ian Islands, birds salvaged as fisheries-bycatch, and birds added to museum collections before 1924. During the chick-rearing season (sampled April-May), means and variances of stable isotope values of birds with the highest, most consistent reproductive success were distinct from less productive conspecifics and completely different from birds caught in Hawaiian or Alaskan longline fisheries, suggesting birds with higher multi-annual reproduc-tive success were less likely to associate with these fisheries. Contemporary birds with the highest reproductive success had mean values most similar to historic birds. Values of col