1
|
Gangoso L, Mateo R, Santamaría-Cervantes C, García-Alfonso M, Gimeno-Castellano C, Arrondo E, Serrano D, van Overveld T, de la Riva M, Cabrera MA, Donázar JA. Blood lead levels in an endangered vulture decline following changes in hunting activity. ENVIRONMENTAL RESEARCH 2024; 252:118712. [PMID: 38548255 DOI: 10.1016/j.envres.2024.118712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024]
Abstract
Lead ammunition stands out as one of the most pervasive pollutants affecting wildlife. Its impact on bird populations have spurred efforts for the phase-out of leaded gunshot in several countries, although with varying scopes and applications. Ongoing and future policy changes require data to assess the effectiveness of adopted measures, particularly in the current context of biodiversity loss. Here, we assessed the long-term changes in blood lead (Pb) levels of Egyptian vultures from the Canary Islands, Spain, which have been severely affected by Pb poisoning over the past two decades. During this period, the reduction in hunting pressure and changes in legislation regarding firearms usage for small game hunting likely contributed to a decrease in environmental Pb availability. As anticipated, our results show a reduction in Pb levels, especially after the ban on wild rabbit hunting with shotgun since 2010. This effect was stronger in the preadult fraction of the vulture population. However, we still observed elevated blood Pb levels above the background and clinical thresholds in 5.6% and 1.5% of individuals, respectively. Our results highlight the positive impact of reducing the availability of Pb from ammunition sources on individual health. Nonetheless, the continued use of Pb gunshot remains an important source of poisoning, even lethal, mainly affecting adult individuals. This poses a particular concern for long-lived birds, compounding by potential chronic effects associated with Pb bioaccumulation. Our findings align with recent studies indicating insufficient reductions in Pb levels among European birds of prey, attributed to limited policy changes and their uneven implementation. We anticipated further reductions in Pb levels among Egyptian vultures with expanded restrictions on hunting practices, including a blanket ban on Pb shot usage across all small game species.
Collapse
Affiliation(s)
- L Gangoso
- Department of Biodiversity, Ecology and Evolution, Faculty of Biological Sciences, Complutense University of Madrid, C/ José Antonio Novais 12, 28040, Madrid, Spain.
| | - R Mateo
- Instituto de Investigación en Recursos Cinegéticos-IREC, CSIC-UCLM-JCCM, Ronda de Toledo 12, 13005, Ciudad Real, Spain
| | - C Santamaría-Cervantes
- Instituto de Investigación en Recursos Cinegéticos-IREC, CSIC-UCLM-JCCM, Ronda de Toledo 12, 13005, Ciudad Real, Spain
| | - M García-Alfonso
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| | - C Gimeno-Castellano
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| | - E Arrondo
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain; Department of Zoology, University of Granada, Avenida Fuente Nueva s/n, 18071, Granada, Spain
| | - D Serrano
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| | - T van Overveld
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| | - M de la Riva
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| | - M A Cabrera
- Dirección general de Espacios Naturales y Biodiversidad. Consejería de Transición Ecológica y Energía, Gobierno de Canarias, C/ Prof. Agustín Millares Carló, 18, 35071, Las Palmas de Gran Canaria, Spain
| | - J A Donázar
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), Américo Vespucio 26, 41092, Sevilla, Spain
| |
Collapse
|
2
|
Fernández-Gómez L, Sánchez-Zapata JA, Donázar JA, Barber X, Barbosa JM. Ecosystem productivity drives the breeding success of an endangered top avian scavenger in a changing grazing pressure context. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 910:168553. [PMID: 37979851 DOI: 10.1016/j.scitotenv.2023.168553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 10/30/2023] [Accepted: 11/11/2023] [Indexed: 11/20/2023]
Abstract
Environmental conditions and resource availability shape population dynamics through direct and indirect effects of climate, biological interactions and the human modification of landscape. Even when a species seems dependent on predictable anthropogenic food resources or subsidies, ecosystem-level factors can still determine population dynamics across taxa. However, there is still a knowledge gap about the cascade effects driven by climate, vegetation functioning, resource availability and governmental policies on key aspects of species reproduction for top scavengers. Here we put to good use 22 years (2000-2021) of extensive population monitoring from the endemic Canary Egyptian vulture (Neophron percnopterus majorensis) on the Fuerteventura Island (Canary Islands, Spain) to study the relative importance of demographic factors, ecosystem conditions and availability of anthropogenic food sources on breeding success. Our results suggest that ecosystem-level primary productivity, the number of livestock animals present on the island and Density-dependent processes determine the temporal changes in the breeding success of this species. We firstly accounted for a top-down effect of livestock on island vegetation, where overgrazing directly reduces landscape-level vegetation biomass. We, consequently, found a bottom-up effect between vegetation and the Egyptian vulture's breeding success. In this context, minimal changes in ecological conditions can impact the species inhabiting these ecosystems, with direct consequences on a key population stage, such as breeding season, when energy requirements are higher. These results are especially relevant because cascading and indirect effects of ecosystem processes and governmental policies are often overlooked when pursuing conservation goals of endangered species.
Collapse
Affiliation(s)
- Lola Fernández-Gómez
- Department of Applied Biology, Centro de Investigación e Innovación Alimentaria (CIAGRO-UMH), Universidad Miguel Hernández de Elche, 03202 Elche, Spain.
| | - José A Sánchez-Zapata
- Department of Applied Biology, Centro de Investigación e Innovación Alimentaria (CIAGRO-UMH), Universidad Miguel Hernández de Elche, 03202 Elche, Spain
| | - José A Donázar
- Department of Conservation Biology, EBD (CSIC), C/. Americo Vespucio 26, 41092 Seville, Spain
| | - Xavier Barber
- Center of Operations Reseach, CIO-UMH, Universidad Miguel Hernández de Elche, 03202 Elche, Spain
| | - Jomar M Barbosa
- Department of Applied Biology, Centro de Investigación e Innovación Alimentaria (CIAGRO-UMH), Universidad Miguel Hernández de Elche, 03202 Elche, Spain
| |
Collapse
|
3
|
Gómez‐López G, Sanz‐Aguilar A, Carrete M, Arrondo E, Benítez JR, Ceballos O, Cortés‐Avizanda A, de Pablo F, Donázar JA, Frías Ó, Gangoso L, García‐Alfonso M, González JL, Grande JM, Serrano D, Tella JL, Blanco G. Insularity determines nestling sex ratio variation in Egyptian vulture populations. Ecol Evol 2023; 13:e10371. [PMID: 37529590 PMCID: PMC10385291 DOI: 10.1002/ece3.10371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/04/2023] [Accepted: 07/11/2023] [Indexed: 08/03/2023] Open
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.
Collapse
Affiliation(s)
- Guillermo Gómez‐López
- Department of Evolutionary Ecology, National Museum of Natural SciencesSpanish National Research CouncilMadridSpain
- Department of Biodiversity, Ecology and Evolution, Faculty of BiologyComplutense University of MadridMadridSpain
| | - Ana Sanz‐Aguilar
- Animal Demography and Ecology GroupInstitut Mediterrani d'Estudis Avançats, Spanish National Research CouncilMallorcaSpain
- Applied Zoology and Conservation GroupUniversitat de les Illes BalearsPalmaSpain
| | - Martina Carrete
- Department of Physical, Chemical and Natural SystemsPablo de Olavide UniversitySevillaSpain
| | - Eneko Arrondo
- Department of ZoologyUniversity of GranadaGranadaSpain
- Department of Applied BiologyMiguel Hernández UniversityElcheSpain
| | - José Ramón Benítez
- Department of BiodiversityAgencia de Medioambiente y Agua, Junta de AndalucíaSevillaSpain
| | | | - Ainara Cortés‐Avizanda
- Department of Plant Biology and EcologyUniversity of SevilleSevillaSpain
- Department of Conservation BiologyDoñana Biological Station, Spanish National Research CouncilSevillaSpain
| | - Félix de Pablo
- Department of Environment and Biosphere ReserveConsell Insular de Menorca, PlazaMaóSpain
| | - José Antonio Donázar
- Department of Conservation BiologyDoñana Biological Station, Spanish National Research CouncilSevillaSpain
| | - Óscar Frías
- Department of Physical, Chemical and Natural SystemsPablo de Olavide UniversitySevillaSpain
| | - Laura Gangoso
- Department of Biodiversity, Ecology and Evolution, Faculty of BiologyComplutense University of MadridMadridSpain
| | - Marina García‐Alfonso
- Department of Conservation BiologyDoñana Biological Station, Spanish National Research CouncilSevillaSpain
| | - José Luis González
- Department of Evolutionary Ecology, National Museum of Natural SciencesSpanish National Research CouncilMadridSpain
| | | | - David Serrano
- Department of Conservation BiologyDoñana Biological Station, Spanish National Research CouncilSevillaSpain
| | - José Luis Tella
- Department of Conservation BiologyDoñana Biological Station, Spanish National Research CouncilSevillaSpain
| | - Guillermo Blanco
- Department of Evolutionary Ecology, National Museum of Natural SciencesSpanish National Research CouncilMadridSpain
| |
Collapse
|
4
|
Abstract
Many large predators are also facultative scavengers that may compete with and depredate other species at carcasses. Yet, the ecological impacts of facultative scavenging by large predators, or their "scavenging effects," still receive relatively little attention in comparison to their predation effects. To address this knowledge gap, we comprehensively examine the roles played by, and impacts of, facultative scavengers, with a focus on large canids: the African wild dog (Lycaon pictus), dhole (Cuon alpinus), dingo (Canis dingo), Ethiopian wolf (Canis simensis), gray wolf (Canis lupus), maned wolf (Chrysocyon brachyurus), and red wolf (Canis rufus). Specifically, after defining facultative scavenging as use or usurpation of a carcass that a consumer has not killed, we (1) provide a conceptual overview of the community interactions around carcasses that can be initiated by facultative scavengers, (2) review the extent of scavenging by and the evidence for scavenging effects of large canids, (3) discuss external factors that may diminish or enhance the effects of large canids as scavengers, and (4) identify aspects of this phenomenon that require additional research attention as a guide for future work.
Collapse
Affiliation(s)
- Aaron J Wirsing
- School of Environment and Forest Sciences, University of Washington, Seattle, WA 98195, USA
| | - Thomas M Newsome
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| |
Collapse
|
5
|
García-Alfonso M, van Overveld T, Gangoso L, Serrano D, Donázar JA. Vultures and Livestock: The Where, When, and Why of Visits to Farms. Animals (Basel) 2020; 10:ani10112127. [PMID: 33207713 PMCID: PMC7698296 DOI: 10.3390/ani10112127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 01/24/2023] Open
Abstract
Recent changes in European legislation have legalized the abandonment of carcasses around livestock farms, but our understanding of how vultures exploit these semi-predictable food sources is still very limited. For filling this gap, we determine the individual and ecological drivers influencing vulture visits to farms. We assessed the effects of individual characteristics of both birds and farms on the frequency of vultures' visits to livestock facilities using data collected from 45 GPS-tagged Egyptian Vultures (Neophron percnopterus) and 318 farms (>94% of livestock) on Fuerteventura Island, Spain. Farms were more visited during the vultures' breeding season. Farms located closer to highly predictable feeding places (i.e., vulture restaurants and garbage dumps) or with more available feeding resources were visited by more vultures, whereas those located close to roads and vultures' breeding territories received fewer visits. Younger territorial birds visited a farm more frequently than older territorial ones, whereas older non-territorial individuals concentrated those visits on farms closer to their activity core areas compared with younger ones. Our findings indicate that visits to farms were determined by their spatial distribution in relation to the age-specific birds' activity centers, the availability of carcasses, seasonality, and individual characteristics of vultures. These interacting factors should be considered in vulture conservation, avoiding very general solutions that ignore population structure.
Collapse
Affiliation(s)
- Marina García-Alfonso
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio 26, 41092 Sevilla, Spain; (T.v.O.); (D.S.); (J.A.D.)
- Correspondence:
| | - Thijs van Overveld
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio 26, 41092 Sevilla, Spain; (T.v.O.); (D.S.); (J.A.D.)
| | - Laura Gangoso
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands;
| | - David Serrano
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio 26, 41092 Sevilla, Spain; (T.v.O.); (D.S.); (J.A.D.)
| | - José A. Donázar
- Department of Conservation Biology, Estación Biológica de Doñana (CSIC), C/Américo Vespucio 26, 41092 Sevilla, Spain; (T.v.O.); (D.S.); (J.A.D.)
| |
Collapse
|
6
|
Barbosa JM, Hiraldo F, Romero MÁ, Tella JL. When does agriculture enter into conflict with wildlife? A global assessment of parrot–agriculture conflicts and their conservation effects. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Jomar M. Barbosa
- Department of Conservation Biology Estación Biológica de DoñanaC.S.I.C. Seville Spain
| | - Fernando Hiraldo
- Department of Conservation Biology Estación Biológica de DoñanaC.S.I.C. Seville Spain
| | - Miguel Á. Romero
- Department of Conservation Biology Estación Biológica de DoñanaC.S.I.C. Seville Spain
| | - José L. Tella
- Department of Conservation Biology Estación Biológica de DoñanaC.S.I.C. Seville Spain
| |
Collapse
|