Food subsidies shape age structure in a top avian scavenger
Human activities and recent changes in sanitary regulations are currently shaping the availability of carrion resources across ecosystems. How changes in regulations influence demographic parameters in avian scavengers is still poorly known. We combine photographic observations gathered by citizens...
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| Format: | Article |
| Language: | English |
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Resilience Alliance
2022-06-01
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| Series: | Avian Conservation and Ecology |
| Subjects: | |
| Online Access: | https://www.ace-eco.org/vol17/iss1/art23/ |
| _version_ | 1828073107720503296 |
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| author | Lola Fernández-Gómez Ainara Cortés-Avizanda Patricia Tiago Fiach Byrne José Antonio. Donázar |
| author_facet | Lola Fernández-Gómez Ainara Cortés-Avizanda Patricia Tiago Fiach Byrne José Antonio. Donázar |
| author_sort | Lola Fernández-Gómez |
| collection | DOAJ |
| description | Human activities and recent changes in sanitary regulations are currently shaping the availability of carrion resources across ecosystems. How changes in regulations influence demographic parameters in avian scavengers is still poorly known. We combine photographic observations gathered by citizens and observational data from research projects in northern Spain to examine if the age structure of Eurasian Griffon Vulture (Gyps fulvus) populations at different trophic resources (natural randomly-distributed carcasses, predictable resources [supplementary feeding sites and farms], and landfills) varied in relation to modifications of sanitary regulations from 2004 onwards. We found that the proportion of immature birds increased significantly after the introduction of new European sanitary regulations allowing farmers to dispose of livestock carcasses in the field, rather than incinerating them. Also, we found that the age structure varied significantly between food resources, such that we detected a higher fraction of immatures at landfills, as well as in sites where carrion was highly clumped. These findings reveal that loss of natural randomness in carrion availability may elicit age-dependent effects on the spatial distribution of the vultures at the mesoscale which may ultimately affect population structure. Our findings shed light on challenges on how to manage food subsidies to preserve avian scavenger populations in an increasingly anthropized world. |
| first_indexed | 2024-04-11T01:22:47Z |
| format | Article |
| id | doaj.art-68fc3405a715447e9713b85e25dd7100 |
| institution | Directory Open Access Journal |
| issn | 1712-6568 |
| language | English |
| last_indexed | 2024-04-11T01:22:47Z |
| publishDate | 2022-06-01 |
| publisher | Resilience Alliance |
| record_format | Article |
| series | Avian Conservation and Ecology |
| spelling | doaj.art-68fc3405a715447e9713b85e25dd71002023-01-03T11:00:01ZengResilience AllianceAvian Conservation and Ecology1712-65682022-06-01171232104Food subsidies shape age structure in a top avian scavengerLola Fernández-Gómez0Ainara Cortés-Avizanda1Patricia Tiago2Fiach Byrne3José Antonio. Donázar4Department of Conservation Biology, EBD (CSIC), Seville, SpainDepartment of Conservation Biology, EBD (CSIC), Seville, SpainCentre for Ecology, Evolution and Environmental Changes (CE3C), Faculdade de Ciências, Universidade de Lisboa, Lisbon, PortugalDepartment of Conservation Biology, EBD (CSIC), Seville, SpainDepartment of Conservation Biology, EBD (CSIC), Seville, SpainHuman activities and recent changes in sanitary regulations are currently shaping the availability of carrion resources across ecosystems. How changes in regulations influence demographic parameters in avian scavengers is still poorly known. We combine photographic observations gathered by citizens and observational data from research projects in northern Spain to examine if the age structure of Eurasian Griffon Vulture (Gyps fulvus) populations at different trophic resources (natural randomly-distributed carcasses, predictable resources [supplementary feeding sites and farms], and landfills) varied in relation to modifications of sanitary regulations from 2004 onwards. We found that the proportion of immature birds increased significantly after the introduction of new European sanitary regulations allowing farmers to dispose of livestock carcasses in the field, rather than incinerating them. Also, we found that the age structure varied significantly between food resources, such that we detected a higher fraction of immatures at landfills, as well as in sites where carrion was highly clumped. These findings reveal that loss of natural randomness in carrion availability may elicit age-dependent effects on the spatial distribution of the vultures at the mesoscale which may ultimately affect population structure. Our findings shed light on challenges on how to manage food subsidies to preserve avian scavenger populations in an increasingly anthropized world.https://www.ace-eco.org/vol17/iss1/art23/demographygriffon vulturegyps fulvusfarmslandfillsresource predictabilitysanitary regulationssupplementary feeding stations |
| spellingShingle | Lola Fernández-Gómez Ainara Cortés-Avizanda Patricia Tiago Fiach Byrne José Antonio. Donázar Food subsidies shape age structure in a top avian scavenger Avian Conservation and Ecology demography griffon vulture gyps fulvus farms landfills resource predictability sanitary regulations supplementary feeding stations |
| title | Food subsidies shape age structure in a top avian scavenger |
| title_full | Food subsidies shape age structure in a top avian scavenger |
| title_fullStr | Food subsidies shape age structure in a top avian scavenger |
| title_full_unstemmed | Food subsidies shape age structure in a top avian scavenger |
| title_short | Food subsidies shape age structure in a top avian scavenger |
| title_sort | food subsidies shape age structure in a top avian scavenger |
| topic | demography griffon vulture gyps fulvus farms landfills resource predictability sanitary regulations supplementary feeding stations |
| url | https://www.ace-eco.org/vol17/iss1/art23/ |
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