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Crosby CH, Schlacher TA, Kerwin K, Maslo B. Impacts of coyote colonization on coastal mammalian predators. Sci Rep 2024; 14:17868. [PMID: 39090258 PMCID: PMC11294349 DOI: 10.1038/s41598-024-68698-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/26/2024] [Indexed: 08/04/2024] Open
Abstract
Extreme ecosystem modification by humans has caused drastic reductions in populations and ranges of top mammalian predators, while simultaneously allowing synanthropic mesopredator species to expand. These conditions often result in inflated local densities of highly adaptable mesopredators that disrupt trophic dynamics and place unsustainable predation pressure on native prey populations. Colonization of a dominant predator may lead to top-down control of mesopredators and restore trophic balance. Coyotes are a novel colonizer of some coastal barrier islands of eastern North America, offering an opportunity to test how the addition of an apex predator impacts an established guild of mesopredators. To assess their trophic impact, we conducted 75,576 camera trapping hours over an 18-month study period, capturing > 1.5 million images across 108 coastal camera sites. Using two-species occupancy and habitat use models, we found sizeable effects of coyote habitat use on that of red foxes and free-ranging domestic cats, suggesting that coyotes function as apex predators in barrier island ecosystems. In fact, the only factor that determined the spatial pattern of highly ubiquitous red foxes was the sympatric habitat use of the largest carnivore in the food web-coyotes. That 'novel' apex predators can become established in coastal food webs illustrates the highly dynamic nature of conservation challenges for habitats and species at the edge of the sea.
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Affiliation(s)
- Christian H Crosby
- Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
| | - Thomas A Schlacher
- School of Science, Engineering and Technology, University of the Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Kathleen Kerwin
- Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA
| | - Brooke Maslo
- Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA
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Restrepo-Cardona JS, Kohn S, Renjifo LM, Vásquez-Restrepo JD, Zuluaga S, Vargas FH, Narváez F, Salagaje LA, Recalde A, Gaitán-López EC, Salazar A, Hull V. Implications of human-wildlife conflict on the diet of an endangered avian top predator in the northern Andes. Sci Rep 2024; 14:13077. [PMID: 38844827 PMCID: PMC11156653 DOI: 10.1038/s41598-024-63947-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 06/03/2024] [Indexed: 06/09/2024] Open
Abstract
Conflicts between rural people and the Endangered Black-and-chestnut Eagle (Spizaetus isidori) are a prominent conservation concern in the northern Andes, as at least 60 eagles were poached between 2000 and 2022 in response to poultry predation. Here, we conducted direct observations to analyze the Black-and-chestnut Eagle diet and evaluated how forest cover affects the feeding habits of the species during nestling-rearing periods in 16 nests located in different human-transformed Andean landscapes of Ecuador and Colombia. We analyzed 853 prey items (46 species) delivered to nestlings. We used Generalized Linear Models to test whether the percent forest cover calculated within varying buffer distances around each nest and linear distances from the nest to the nearest settlement and pasture areas were predictors of diet diversity and biomass contribution of prey. Forest cover was not a factor that affected the consumption of poultry; however, the eagle regularly preyed on chickens (Gallus gallus) (i.e., domestic Galliformes) which were consumed by 15 of the 16 eagle pairs, with biomass contributions (14.57% ± 10.55) representing 0.6-37% of the total prey consumed. The Black-and-chestnut Eagle is an adaptable generalist able to switch from mammalian carnivores to guans (i.e., wild Galliformes) in human-dominated landscapes, and eagles nesting in sites with low forest cover had a less diverse diet than those in areas with more intact forests. Management actions for the conservation of this avian top predator require studies on the eagle's diet in areas where human persecution is suspected or documented, but also maintaining forest cover for the wild prey of the species, development of socio-economic and psychological assessments on the drivers behind human-eagle conflicts, and the strengthening of technical capacities of rural communities, such as appropriate poultry management.
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Affiliation(s)
- Juan Sebastián Restrepo-Cardona
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA.
- Fundación Cóndor Andino, Quito, Ecuador.
| | | | - Luis Miguel Renjifo
- Departamento de Ecología y Territorio, Facultad de Estudios Ambientales y Rurales, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Juan D Vásquez-Restrepo
- Laboratorio de Herpetología, Museo de Zoología "Alfonso L. Herrera", Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Santiago Zuluaga
- Fundación Cóndor Andino, Quito, Ecuador
- Colaboratorio de Biodiversidad, Ecología y Conservación (INCITAP-CONICET/FCEyN-UNLPam), Santa Rosa, Argentina
- Fundación Proyecto Águila Crestada-Colombia, Manizales, Colombia
| | - Félix Hernán Vargas
- Fundación Cóndor Andino, Quito, Ecuador
- The Peregrine Fund, Galápagos, Ecuador
| | | | | | | | | | | | - Vanessa Hull
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA
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Kaizer M, Fabres B, Aguiar-Silva FH, Sanaiotti TM, Dias AR, Banhos A. The prey of the Harpy Eagle in its last reproductive refuges in the Atlantic Forest. Sci Rep 2023; 13:18308. [PMID: 37880262 PMCID: PMC10600338 DOI: 10.1038/s41598-023-44014-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 10/03/2023] [Indexed: 10/27/2023] Open
Abstract
The Harpy Eagle (Harpia harpyja) is threatened with extinction throughout its distribution in the neotropical forests. In the Atlantic Forest, deforestation has reduced the number of suitable habitats, with only a few remnant forest fragments hosting active nests; currently, the only known nests in this region are in the Central Atlantic Forest Ecological Corridor (CAFEC), in Brazil. Little is known about Harpy Eagle diets in this region, despite this information being essential for developing effective conservation strategies. We classified the composition, frequency, richness, ecological attributes, and conservation status of the species that make up the Harpy Eagle's diet in its last refuges in the CAFEC. Between 2017 and 2021, we collected and analyzed 152 prey remains and 285 camera trap photographs from seven active nests. We identified at least 16 mammal species (96.7%), one parrot and other bird remains (3.3%). The Harpy Eagle's diet consisted mainly of medium-sized arboreal, folivorous, frugivorous, and diurnal mammals. Five prey species are currently threatened with extinction at global, six at national and seven at regional levels. The majority of the diet consists of Sapajus robustus, which is threatened, and Bradypus variegatus, which is not threatened. In addition to the effects of habitat loss and hunting, the Harpy Eagle may also suffer from the decline in the populations of their prey in the Atlantic Forest.
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Affiliation(s)
- Mylena Kaizer
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
- Projeto Harpia (Harpy Eagle Project - Brazil), Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Aleixo, Manaus, Amazonas, 69067-375, Brazil
- Programa de Pós-Graduação em Zoologia - PPGZOOL, Universidade Federal do Amazonas - UFAM, Av. General Rodrigo Otávio Jordão Ramos, 3000, Coroado, Manaus, Amazonas, 69077-000, Brazil
| | - Brener Fabres
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
- Projeto Harpia (Harpy Eagle Project - Brazil), Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Aleixo, Manaus, Amazonas, 69067-375, Brazil
- Programa de Pós-Graduação em Ciências Biológicas (Biologia Animal) - PPGBAN, Universidade Federal do Espírito Santo - UFES, Avenida Fernando Ferrari, 514, Prédio Barbara Weinberg, Vitória, Espírito Santo, 29075-910, Brazil
| | - Francisca Helena Aguiar-Silva
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
- Projeto Harpia (Harpy Eagle Project - Brazil), Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Aleixo, Manaus, Amazonas, 69067-375, Brazil
- Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia - INPA, Avenida André Araújo, 2936, Petrópolis, Manaus, Amazonas, 69067-375, Brazil
| | - Tânia Margarete Sanaiotti
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
- Projeto Harpia (Harpy Eagle Project - Brazil), Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Aleixo, Manaus, Amazonas, 69067-375, Brazil
- Coordenação de Biodiversidade, Instituto Nacional de Pesquisas da Amazônia - INPA, Avenida André Araújo, 2936, Petrópolis, Manaus, Amazonas, 69067-375, Brazil
| | - Alexandro Ribeiro Dias
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil
- Reserva Particular de Patrimônio Natural Estação Veracel, Rodovia BR-367, 37, Porto Seguro, Bahia, 45810-000, Brazil
| | - Aureo Banhos
- Projeto Harpia - Mata Atlântica (Harpy Eagle Project - Atlantic Forest), Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil.
- Projeto Harpia (Harpy Eagle Project - Brazil), Instituto Nacional de Pesquisas da Amazônia - INPA, Av. André Araújo, 2936, Aleixo, Manaus, Amazonas, 69067-375, Brazil.
- Programa de Pós-Graduação em Ciências Biológicas (Biologia Animal) - PPGBAN, Universidade Federal do Espírito Santo - UFES, Avenida Fernando Ferrari, 514, Prédio Barbara Weinberg, Vitória, Espírito Santo, 29075-910, Brazil.
- Departamento de Biologia, Centro de Ciências Exatas, Naturais e da Saúde, Universidade Federal do Espírito Santo - UFES, Alto Universitário, Guararema, Alegre, Espírito Santo, 29500-000, Brazil.
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