Insularity determines nestling sex ratio variation in Egyptian vulture populations
Abstract 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 s...
| Main Authors: | , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2023-08-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.10371 |
| _version_ | 1797732761761480704 |
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| author | Guillermo Gómez‐López Ana Sanz‐Aguilar Martina Carrete Eneko Arrondo José Ramón Benítez Olga Ceballos Ainara Cortés‐Avizanda Félix dePablo José Antonio Donázar Óscar Frías Laura Gangoso Marina García‐Alfonso José Luis González Juan Manuel Grande David Serrano José Luis Tella Guillermo Blanco |
| author_facet | Guillermo Gómez‐López Ana Sanz‐Aguilar Martina Carrete Eneko Arrondo José Ramón Benítez Olga Ceballos Ainara Cortés‐Avizanda Félix dePablo José Antonio Donázar Óscar Frías Laura Gangoso Marina García‐Alfonso José Luis González Juan Manuel Grande David Serrano José Luis Tella Guillermo Blanco |
| author_sort | Guillermo Gómez‐López |
| collection | DOAJ |
| description | Abstract 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. |
| first_indexed | 2024-03-12T12:18:10Z |
| format | Article |
| id | doaj.art-e916691c09194b8ba7c84e0fb8d1c0c7 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-03-12T12:18:10Z |
| publishDate | 2023-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-e916691c09194b8ba7c84e0fb8d1c0c72023-08-30T06:50:40ZengWileyEcology and Evolution2045-77582023-08-01138n/an/a10.1002/ece3.10371Insularity determines nestling sex ratio variation in Egyptian vulture populationsGuillermo Gómez‐López0Ana Sanz‐Aguilar1Martina Carrete2Eneko Arrondo3José Ramón Benítez4Olga Ceballos5Ainara Cortés‐Avizanda6Félix dePablo7José Antonio Donázar8Óscar Frías9Laura Gangoso10Marina García‐Alfonso11José Luis González12Juan Manuel Grande13David Serrano14José Luis Tella15Guillermo Blanco16Department of Evolutionary Ecology, National Museum of Natural Sciences Spanish National Research Council Madrid SpainAnimal Demography and Ecology Group Institut Mediterrani d'Estudis Avançats, Spanish National Research Council Mallorca SpainDepartment of Physical, Chemical and Natural Systems Pablo de Olavide University Sevilla SpainDepartment of Zoology University of Granada Granada SpainDepartment of Biodiversity Agencia de Medioambiente y Agua, Junta de Andalucía Sevilla SpainUGARRA Pamplona SpainDepartment of Plant Biology and Ecology University of Seville Sevilla SpainDepartment of Environment and Biosphere Reserve Consell Insular de Menorca, Plaza Maó SpainDepartment of Conservation Biology Doñana Biological Station, Spanish National Research Council Sevilla SpainDepartment of Physical, Chemical and Natural Systems Pablo de Olavide University Sevilla SpainDepartment of Biodiversity, Ecology and Evolution, Faculty of Biology Complutense University of Madrid Madrid SpainDepartment of Conservation Biology Doñana Biological Station, Spanish National Research Council Sevilla SpainDepartment of Evolutionary Ecology, National Museum of Natural Sciences Spanish National Research Council Madrid SpainColBEC, INCITAP‐CONICET‐UNLPam/FCEyN‐UNLPam Santa Rosa ArgentinaDepartment of Conservation Biology Doñana Biological Station, Spanish National Research Council Sevilla SpainDepartment of Conservation Biology Doñana Biological Station, Spanish National Research Council Sevilla SpainDepartment of Evolutionary Ecology, National Museum of Natural Sciences Spanish National Research Council Madrid SpainAbstract 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.https://doi.org/10.1002/ece3.10371demographyislandsNeophron percnopterusnestling sexoffspring sex ratiosex sequence |
| spellingShingle | Guillermo Gómez‐López Ana Sanz‐Aguilar Martina Carrete Eneko Arrondo José Ramón Benítez Olga Ceballos Ainara Cortés‐Avizanda Félix dePablo José Antonio Donázar Óscar Frías Laura Gangoso Marina García‐Alfonso José Luis González Juan Manuel Grande David Serrano José Luis Tella Guillermo Blanco Insularity determines nestling sex ratio variation in Egyptian vulture populations Ecology and Evolution demography islands Neophron percnopterus nestling sex offspring sex ratio sex sequence |
| title | Insularity determines nestling sex ratio variation in Egyptian vulture populations |
| title_full | Insularity determines nestling sex ratio variation in Egyptian vulture populations |
| title_fullStr | Insularity determines nestling sex ratio variation in Egyptian vulture populations |
| title_full_unstemmed | Insularity determines nestling sex ratio variation in Egyptian vulture populations |
| title_short | Insularity determines nestling sex ratio variation in Egyptian vulture populations |
| title_sort | insularity determines nestling sex ratio variation in egyptian vulture populations |
| topic | demography islands Neophron percnopterus nestling sex offspring sex ratio sex sequence |
| url | https://doi.org/10.1002/ece3.10371 |
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