Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle

Population genetics is an invaluable tool for studying and conserving scarcely researched and elusive threatened species. The Chaco eagle (Buteogallus coronatus) is one of the rarest and most severely threatened raptors in the Neotropical region, and due to its elusiveness, many aspects of the speci...

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Main Authors: David Canal, Juan José Negro, José Hernán Sarasola
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Global Ecology and Conservation
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Online Access:http://www.sciencedirect.com/science/article/pii/S2351989425002094
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author David Canal
Juan José Negro
José Hernán Sarasola
author_facet David Canal
Juan José Negro
José Hernán Sarasola
author_sort David Canal
collection DOAJ
description Population genetics is an invaluable tool for studying and conserving scarcely researched and elusive threatened species. The Chaco eagle (Buteogallus coronatus) is one of the rarest and most severely threatened raptors in the Neotropical region, and due to its elusiveness, many aspects of the species' life history, with important conservation implications, remain mostly unknown. Here, relying primarily on non-invasive DNA sampling at a large spatio-temporal scale, we investigate the reproductive strategies of the Chaco eagle. Over twelve years (2002–2014), we collected 87 moulted feathers from territorial individuals and blood samples from 32 nestlings at 30 nesting sites distributed across a large region (approximately 30,000 km2) of semiarid habitats in Argentina. A primary aim was to elucidate whether this species breeds on a two-year cycle basis, a crucial but still unclear aspect of its life history since, if confirmed, this delay would impose a significant limitation on the lifetime productivity of Chaco eagles across its entire range. We also investigated the occurrence of pair substitutions and territory changes between reproductive events, factors likely intertwined with adult mortality rates and anthropogenic pressures. We found conclusive evidence that eagles may breed annually. In addition, our data suggest that the replacement of a pair member and/or the breeding dispersal to another territory (up to 30 km away) is not uncommon in the species, presumably due to human-related mortality. These spatial patterns of breeding territory selection and breeding dispersal have never been described for large eagles in the Neotropics and highlight the potential ecological consequences of human pressure on this keystone species. Overall, these findings bear direct implications for the demographic dynamics, management, and conservation strategies of the Chaco eagle.
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spelling doaj-art-2db0f661300a4592bbb6918be6be0cea2025-08-20T02:25:30ZengElsevierGlobal Ecology and Conservation2351-98942025-08-0160e0360810.1016/j.gecco.2025.e03608Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco EagleDavid Canal0Juan José Negro1José Hernán Sarasola2Department of Evolutionary Ecology, National Museum of Natural Sciences (MNCN-CSIC), José Gutiérrez Abascal, 2, Madrid 28006, Spain; Corresponding author.Department of Evolutionary Ecology, Doñana Biological Station– CSIC, Av. Américo Vespucio s/n, Seville 41092, SpainCentro para el Estudio y Conservación de las Aves Rapaces en Argentina (CECARA), Universidad Nacional de La Pampa, Avda. Uruguay 151, Santa Rosa, La Pampa 6300, Argentina; Instituto de las Ciencias Ambientales y de la Tierra de La Pampa (INCITAP-CONICET), Avda. Uruguay 151, Santa Rosa, La Pampa 6300, Argentina; The Peregrine Fund, 5668 West Flying Hawk Lane, Boise, ID 83709, USAPopulation genetics is an invaluable tool for studying and conserving scarcely researched and elusive threatened species. The Chaco eagle (Buteogallus coronatus) is one of the rarest and most severely threatened raptors in the Neotropical region, and due to its elusiveness, many aspects of the species' life history, with important conservation implications, remain mostly unknown. Here, relying primarily on non-invasive DNA sampling at a large spatio-temporal scale, we investigate the reproductive strategies of the Chaco eagle. Over twelve years (2002–2014), we collected 87 moulted feathers from territorial individuals and blood samples from 32 nestlings at 30 nesting sites distributed across a large region (approximately 30,000 km2) of semiarid habitats in Argentina. A primary aim was to elucidate whether this species breeds on a two-year cycle basis, a crucial but still unclear aspect of its life history since, if confirmed, this delay would impose a significant limitation on the lifetime productivity of Chaco eagles across its entire range. We also investigated the occurrence of pair substitutions and territory changes between reproductive events, factors likely intertwined with adult mortality rates and anthropogenic pressures. We found conclusive evidence that eagles may breed annually. In addition, our data suggest that the replacement of a pair member and/or the breeding dispersal to another territory (up to 30 km away) is not uncommon in the species, presumably due to human-related mortality. These spatial patterns of breeding territory selection and breeding dispersal have never been described for large eagles in the Neotropics and highlight the potential ecological consequences of human pressure on this keystone species. Overall, these findings bear direct implications for the demographic dynamics, management, and conservation strategies of the Chaco eagle.http://www.sciencedirect.com/science/article/pii/S2351989425002094Birds of preyBreeding dispersalButeogallus coronatusDemographyMortalityPopulation genetics
spellingShingle David Canal
Juan José Negro
José Hernán Sarasola
Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
Global Ecology and Conservation
Birds of prey
Breeding dispersal
Buteogallus coronatus
Demography
Mortality
Population genetics
title Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
title_full Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
title_fullStr Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
title_full_unstemmed Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
title_short Non-invasive DNA monitoring unveils the reproductive strategy of an endangered and elusive top predator, the Chaco Eagle
title_sort non invasive dna monitoring unveils the reproductive strategy of an endangered and elusive top predator the chaco eagle
topic Birds of prey
Breeding dispersal
Buteogallus coronatus
Demography
Mortality
Population genetics
url http://www.sciencedirect.com/science/article/pii/S2351989425002094
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