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Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/122843

Age-dependent survival of island vs. mainland populations of two avian scavengers: delving into migration costs

AutorSanz-Aguilar, Ana ; De Pablo, Félix; Donázar, José A.
Palabras claveNeophron percnopterus
Milvus milvus
Fecha de publicaciónoct-2015
CitaciónOecologia 179(2): 405-414 (2015)
ResumenLarge terrestrial long-lived birds (including raptors) are typically sedentary on islands, even when they are migratory on the mainland. Density-dependent variation in the age at first breeding has been described as responsible for the long-term persistence of long-lived bird populations on islands. However, sedentary island populations may also benefit from higher survival rates derived from the absence of migration costs, especially for young individuals. Thus, sedentary island populations can mimic a natural experiment to study migration costs. We estimated the age-dependent survival of two sedentary raptors on the island of Menorca (Egyptian vultures Neophron percnopterus and red kites Milvus milvus) and compared these estimates with those reported for other migratory and sedentary populations. In Menorca, Egyptian vultures, but not red kites, showed low levels of human-related mortality resulting in extremely high survival probabilities, probably due to different diet choices and behavioral patterns. Juvenile Egyptian vultures and red kites in the studied population had lower survival probabilities than adults. This difference, however, was smaller than those reported for mainland migrant populations, which showed a lower juvenile survival rate. In fact, between-population comparisons suggested that survival of the young in migrant populations may be triggered by mortality factors in wintering areas. In contrast, adult survival may respond to mortality factors in breeding areas. Our results suggest that raptor species that become sedentary on islands may benefit from higher pre-breeder survival prospects in comparison with their mainland migrant counterparts. This fact, in combination with an earlier age at first reproduction, may facilitate their persistence.
Versión del editorhttp://dx.doi.org/10.1007/s00442-015-3355-x
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Sanz-Aguilar et al Egypt vult _Red_kites OECO_D_14_01372 R1.pdf680,2 kBAdobe PDFVista previa
Appendix 1.pdf171,4 kBAdobe PDFVista previa
Appendix 2 corrected.pdf172,48 kBAdobe PDFVista previa
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