Selection against immigrants in wild seabird populations

• Published in: Ecology Letters
• Main Authors: Barbraud, Christophe, Delord, Karine
• Other Authors: de Bruyn, Nico
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Fulmar; Nivea; Diomedea exulans; Snow Petrel; Wandering Albatross
• Online Access: http://dx.doi.org/10.1111/ele.13624; https://onlinelibrary.wiley.com/doi/pdf/10.1111/ele.13624; https://onlinelibrary.wiley.com/doi/full-xml/10.1111/ele.13624

Abstract Immigration is a major demographic parameter shaping population dynamics and is an important driver of eco‐evolutionary patterns, but the fitness consequences for individuals following their settlement to a new population (immigrants) remain poorly tested in wild animal populations, particularly among long‐lived species. Here we show that immigrants have a lower fitness than residents in three wild seabird populations (wandering albatross Diomedea exulans , southern fulmar Fulmarus glacialoides , snow petrel Pagodroma nivea ). Across all species and during a 32‐year period, immigrants made on average −9 to 29% fewer breeding attempts, had 5–31% fewer fledglings, had 2–16% lower breeding success and produced 6–46% fewer recruits. Female immigration and male residency were also favored through differences in breeding performance. We provide evidence for selection against immigrants in wild populations of long‐lived species and our results are consistent with female‐biased dispersal in birds being driven by asymmetric limiting resources and the competitive ability of dispersers vs. non‐dispersers.