Age and sexual differences in the exploitation of two anthropogenic food resources for an opportunistic seabird

摘要: The availability of food resources has been suggested as a major factor in the substantial increase reproductive output, survival, recruitment and, ultimately, population growth rates most organisms. In fact, artificial resulting from human activities size several seabirds recent decades. present study, our primary aim was to estimate importance main natural prey and two alternative feeding resources, fishery discards invasive American crayfish Procambarus clarkii, for an opportunistic seabird, Audouin’s gull Larus audouinii. We also assessed influence age sex use those three types food. For this purpose, we compared analyses δ15N δ13C blood male female adults known chicks with their potential prey. Our results reveal sex-related age-related differences consumption fish discards, small pelagic crayfish. Differences diet males females between could be related different nutritional requirements. Age were probably foraging proficiency tendency young breeders opportunistically exploit anthropogenically derived This study illustrates considering individuals obtain feasible dietary information understand how exploitation origin affect growth.