RT Journal Article
T1 Insularity determines nestling sex ratio variation in Egyptian vulture populations
A1 Gómez López, Guillermo
A1 Sanz Aguilar, Ana
A1 Carrete, Martina
A1 Arrondo, Eneko
A1 Benítez, José Ramón
A1 Ceballos, Olga
A1 Cortés Avizanda, Ainara
A1 Pablo, Félix de
A1 Donázar, José Antonio
A1 Frías, Óscar
A1 Gangoso De La Colina, Laura Esther
A1 García Alfonso, Marina
A1 González, José Luis
A1 Grande, Juan Manuel
A1 Serrano, David
A1 Tella, José Luis
A1 Blanco, Guillermo
AB Variation in offspring sex ratio, particularly in birds, has been frequently studied over the last century, although seldom using long-term monitoring data. In raptors, the cost of raising males and females is not equal, and several variables have been found to have significant effects on sex ratio, including food availability, parental age, and hatching order. Sex ratio differences between island populations and their mainland counterparts have been poorly documented, despite broad scientific literature on the island syndrome reporting substantial differences in population demography and ecology. Here, we assessed individual and environmental factors potentially affecting the secondary sex ratio of the long-lived Egyptian vulture Neophron percnopterus. We used data collected from Spanish mainland and island populations over a ca. 30-year period (1995–2021) to assess the effects of insularity, parental age, breeding phenology, brood size, hatching order, type of breeding unit (pairs vs. trios), and spatial and temporal variability on offspring sex ratio. No sex bias was found at the population level, but two opposite trends were observed between mainland and island populations consistent with the island syndrome. Offspring sex ratio was nonsignificantly female-biased in mainland Spain (0.47, n = 1112) but significantly male-biased in the Canary Islands (0.55, n = 499), where a male-biased mortality among immatures could be compensating for offspring biases and maintaining a paired adult sex ratio. Temporal and spatial variation in food availability might also have some influence on sex ratio, although the difficulties in quantifying them preclude us from determining the magnitude of such influence. This study shows that insularity influences the offspring sex ratio of the Egyptian vulture through several processes that can affect island and mainland populations differentially. Our research contributes to improving our understanding of sex allocation theory by investigating whether sex ratio deviations from parity are possible as a response to changing environments comprised by multiple and complexly interrelated factors.
PB Wiley
SN 2045-7758
YR 2023
FD 2023
LK https://hdl.handle.net/20.500.14352/110972
UL https://hdl.handle.net/20.500.14352/110972
LA eng
NO Gómez-López, G., Sanz-Aguilar, A., Carrete, M., Arrondo, E., Benítez, J. R., Ceballos, O., Cortés-Avizanda, A., de Pablo, F., Donázar, J. A., Frías, Ó., Gangoso, L., García-Alfonso, M., González, J. L., Grande, J. M., Serrano, D., Tella, J. L., & Blanco, G. (2023). Insularity determines nestling sex ratio variation in Egyptian vulture populations. Ecology and Evolution, 13, e10371. https://doi.org/10.1002/ece3.10371
NO Research was funded and supported by the Spanish Ministry of Economy, Industry and Competitiveness (CGL2007-61395, CGL2010-15726, CGL2013-42451-P), the Spanish Ministry of Science and Innovation (PID2019-109685GB-I00, RTI2018-099609-B-C21), Junta de Andalucía (P18-RT-1321, EMERIGIA 2021.1524, FEDER 2021_1073), Diputación General de Aragón, Gobierno de las Islas Baleares, Gobierno de Canarias, Cabildo Insular de Fuerteventura, Junta de Castilla y León, and Comunidad de Bardenas Reales de Navarra. G.G.L. was supported by a FPU fellowship of the Spanish Ministry of Science, Innovation and Universities (FPU19/06511). A.S.A. was supported by a Ramón y Cajal fellowship of the Spanish Ministry of Science (RYC-2017-22796). E.A. was supported by La Caixa-Severo Ochoa International PhD Program 2015; Generalitat Valenciana and European Social Fund (APOSTD/2021), and Spanish Ministry of Science, Innovation and Universities Contracts (FJC2021-047885-I). M.G.A. was supported by a contract from “Programa de FPU del Ministerio de Educación, Cultura y Deporte” (FPU13/05429). A.C.A. was supported by EMERGIA Program from Junta de Andalucía. IMEDEA is an accredited “Maria de Maeztu Excellence Unit” (ref. CEX2021-001198/funded by MCIN/AEI/10.13039/501100011033).
NO Ministerio de Economía y Competitividad (España)
NO Ministerio de Ciencia e Innovación (España)
NO Junta de Andalucía
NO European Commission
NO Diputación General de Aragón
NO Gobierno de las Islas Baleares
NO Gobierno de Canarias
NO Cabildo Insular de Fuerteventura
NO Junta de Castilla y León
NO Comunidad de Bardenas Reales de Navarra
NO La Caixa
NO Generalitat Valenciana
NO Ministerio de Educación, Cultura y Deporte (España)
DS Docta Complutense
RD 9 abr 2025