TY - JOUR
T1 - Differential survival throughout the full annual cycle of a migratory bird presents a life-history trade-off
AU - Buechley, Evan R.
AU - Oppel, Steffen
AU - Efrat, Ron
AU - Phipps, W. Louis
AU - Carbonell Alanís, Isidoro
AU - Álvarez, Ernesto
AU - Andreotti, Alessandro
AU - Arkumarev, Volen
AU - Berger-Tal, Oded
AU - Bermejo Bermejo, Ana
AU - Bounas, Anastasios
AU - Ceccolini, Guido
AU - Cenerini, Anna
AU - Dobrev, Vladimir
AU - Duriez, Olivier
AU - García, Javier
AU - García-Ripollés, Clara
AU - Galán, Manuel
AU - Gil, Alberto
AU - Giraud, Lea
AU - Hatzofe, Ohad
AU - Iglesias-Lebrija, Juan José
AU - Karyakin, Igor
AU - Kobierzycki, Erik
AU - Kret, Elzbieta
AU - Loercher, Franziska
AU - López-López, Pascual
AU - Miller, Ygal
AU - Mueller, Thomas
AU - Nikolov, Stoyan C.
AU - de la Puente, Javier
AU - Sapir, Nir
AU - Saravia, Victoria
AU - Şekercioğlu, Çağan H.
AU - Sillett, T. Scott
AU - Tavares, José
AU - Urios, Vicente
AU - Marra, Peter P.
N1 - Publisher Copyright:
© 2021 British Ecological Society
PY - 2021/5
Y1 - 2021/5
N2 - Long-distance migrations are among the most physically demanding feats animals perform. Understanding the potential costs and benefits of such behaviour is a fundamental question in ecology and evolution. A hypothetical cost of migration should be outweighed by higher productivity and/or higher annual survival, but few studies on migratory species have been able to directly quantify patterns of survival throughout the full annual cycle and across the majority of a species’ range. Here, we use telemetry data from 220 migratory Egyptian vultures Neophron percnopterus, tracked for 3,186 bird months and across approximately 70% of the species’ global distribution, to test for differences in survival throughout the annual cycle. We estimated monthly survival probability relative to migration and latitude using a multi-event capture–recapture model in a Bayesian framework that accounted for age, origin, subpopulation and the uncertainty of classifying fates from tracking data. We found lower survival during migration compared to stationary periods (β = −0.816; 95% credible interval: −1.290 to −0.318) and higher survival on non-breeding grounds at southern latitudes (<25°N; β = 0.664; 0.076–1.319) compared to on breeding grounds. Survival was also higher for individuals originating from Western Europe (β = 0.664; 0.110–1.330) as compared to further east in Europe and Asia, and improved with age (β = 0.030; 0.020–0.042). Anthropogenic mortalities accounted for half of the mortalities with a known cause and occurred mainly in northern latitudes. Many juveniles drowned in the Mediterranean Sea on their first autumn migration while there were few confirmed mortalities in the Sahara Desert, indicating that migration barriers are likely species-specific. Our study advances the understanding of important fitness trade-offs associated with long-distance migration. We conclude that there is lower survival associated with migration, but that this may be offset by higher non-breeding survival at lower latitudes. We found more human-caused mortality farther north, and suggest that increasing anthropogenic mortality could disrupt the delicate migration trade-off balance. Research to investigate further potential benefits of migration (e.g. differential productivity across latitudes) could clarify how migration evolved and how migrants may persist in a rapidly changing world.
AB - Long-distance migrations are among the most physically demanding feats animals perform. Understanding the potential costs and benefits of such behaviour is a fundamental question in ecology and evolution. A hypothetical cost of migration should be outweighed by higher productivity and/or higher annual survival, but few studies on migratory species have been able to directly quantify patterns of survival throughout the full annual cycle and across the majority of a species’ range. Here, we use telemetry data from 220 migratory Egyptian vultures Neophron percnopterus, tracked for 3,186 bird months and across approximately 70% of the species’ global distribution, to test for differences in survival throughout the annual cycle. We estimated monthly survival probability relative to migration and latitude using a multi-event capture–recapture model in a Bayesian framework that accounted for age, origin, subpopulation and the uncertainty of classifying fates from tracking data. We found lower survival during migration compared to stationary periods (β = −0.816; 95% credible interval: −1.290 to −0.318) and higher survival on non-breeding grounds at southern latitudes (<25°N; β = 0.664; 0.076–1.319) compared to on breeding grounds. Survival was also higher for individuals originating from Western Europe (β = 0.664; 0.110–1.330) as compared to further east in Europe and Asia, and improved with age (β = 0.030; 0.020–0.042). Anthropogenic mortalities accounted for half of the mortalities with a known cause and occurred mainly in northern latitudes. Many juveniles drowned in the Mediterranean Sea on their first autumn migration while there were few confirmed mortalities in the Sahara Desert, indicating that migration barriers are likely species-specific. Our study advances the understanding of important fitness trade-offs associated with long-distance migration. We conclude that there is lower survival associated with migration, but that this may be offset by higher non-breeding survival at lower latitudes. We found more human-caused mortality farther north, and suggest that increasing anthropogenic mortality could disrupt the delicate migration trade-off balance. Research to investigate further potential benefits of migration (e.g. differential productivity across latitudes) could clarify how migration evolved and how migrants may persist in a rapidly changing world.
KW - Egyptian vulture
KW - Neophron percnopterus
KW - evolutionary ecology
KW - life-history theory
KW - migration cost
KW - movement ecology
KW - satellite telemetry
KW - survival
UR - http://www.scopus.com/inward/record.url?scp=85103432172&partnerID=8YFLogxK
U2 - 10.1111/1365-2656.13449
DO - 10.1111/1365-2656.13449
M3 - Article
C2 - 33786863
AN - SCOPUS:85103432172
SN - 0021-8790
VL - 90
SP - 1228
EP - 1238
JO - Journal of Animal Ecology
JF - Journal of Animal Ecology
IS - 5
ER -