Habitat

The Black-and-chestnut Eagle prefers middle- to high-elevation montane forests, usually from 1,300–3,000 m, and occasionally lower to sea level, or higher at up to 3,500 m (38 Fjeldså, J., and N. Krabbe (1990). Birds of the High Andes: A Manual to the Birds of the Temperate Zone of the Andes and Patagonia, South America. Zoological Museum, University of Copenhagen and Apollo Books, Copenhagen and Svendborg, Denmark. Close , 39 Bierregaard, R. O. (1994). Black-and-chestnut Eagle. In Handbook of Birds of the World. Volume 2. New World Vultures to Guineafowl (J. del Hoyo, A. Elliott, and J. Saragatal, Editors), Lynx Edicions, Barcelona, Spain. pp. 205. Close , 3 Ferguson-Lees, J., and D. A. Christie (2001). Raptors of the World. Christopher Helm, London, UK. Close ). It is mainly associated with old-growth primary forests, but also visits or even nests in secondary forests surrounded by primary forests, but in such cases it uses large emergent trees (27 Valdez, U., and S. Osborn (2004). Observations on the ecology of the black-and-chestnut eagle (Oroaetus isidori) in a montane forest of southeastern Peru. Ornitología Neotropical 15:31-40. Close , 37 Aráoz, R., J. M. Grande, C. López, J. Cereghetti, and F. H. Vargas (2017). The first Black-and-Chestnut Eagle (Spizaetus isidori) nest discovered in Argentina reveals potential human-predator conflicts. Journal of Raptor Research 51(1):79–82. Close , 40 Zuluaga, S., J. M. Grande, D. F. Aristizábal, and G. Guevara (2018). Parental dependence of a juvenile Black-and-chestnut Eagle (Spizaetus isidori) in the eastern Andes, Colombia. Ornitología Neotropical 29:153–158. Close , 41 Zuluaga, S., J. M. Grande, M. Schulze, D. F. Aristizabal, F. H. Vargas, and F. H. Aguiar-Silva (2018). Nest records of two large eagles in Colombia and Ecuador. Journal of Raptor Research 52:522-527. Close , TRF, unpublished data). It hunts mainly in mature forests, occasionally in open land, as well as in the ecotone between them.

Venezuela

It is found in tropical and subtropical zones, in mesophilic forest with great ecological breadth, and occupying three elevational bands from 400 to 3,000 m; it has also been recorded in the paramo above 3,500 m (42 Schäfer, E., and W. H. Phelps (1954). Las Aves del Parque Nacional Henri Pittier (Rancho Grande) y sus Funciones Ecológicas. Boletín de la Sociedad Venezolana de Ciencias Naturales 16(83). pp. 165. Close ).

Colombia

It mainly occurs on the foothills and slopes of the three mountain ranges of the Andes (eastern, central, and western) and the Sierra Nevada de Santa Marta, in cloud forests between 1,500–3,000 m (24 Márquez, C., M. Bechard, F. Gast, and V. H. Vanegas (2005). Aves Rapaces Diurnas de Colombia. Instituto de Investigación de Recursos Biológicos "Alexander von Humboldt", Bogotá, D. C., Colombia. Close ).

Ecuador

It occurs in premontane and montane forest in both slopes of the Andes, and montane forests of the inter-Andean valley, inter-Andean scrub, and páramo (26 Freile, J., and R. Restall (2018). Birds of Ecuador. Bloomsbury, London, UK. Close ), usually between 1,500–2,800 m, although it can occur up to 3,500 m.

Peru

It is found in humid montane forest of the eastern Andean slope, from 1,000–3,200 m, occasionally 800–3,500 m (27 Valdez, U., and S. Osborn (2004). Observations on the ecology of the black-and-chestnut eagle (Oroaetus isidori) in a montane forest of southeastern Peru. Ornitología Neotropical 15:31-40. Close , 29 Schulenberg, T. S., D. F. Stotz, D. F. Lane, J. P. O’Neill, and T. A. Parker (2010). Birds of Peru. Revised edition. Princeton University Press, Princeton, NJ, USA. Close , Rivas-Fuenzalida et al., unpublished data).

Bolivia

It is found in contiguous, intact, semi-humid to wet montane forest from 900–3,000 m, occasionally 550–3,400 m (30 Herzog, S. K., R. S. Terrill, A. E. Jahn, J. V. Remsen Jr., O. Maillard Z., V. H. García-Solíz, R. MacLeod, A. Maccormick, and J. Q. Vidoz (2016). Birds of Bolivia: Field Guide. Asociación Armonía, Santa Cruz de la Sierra, Bolivia. Close , D. Méndez, personal communication).

Argentina

It occurs in yungas or subtropical montane forests at altitudes ranging from 500–2,000 m. It is also recorded at higher elevations in montane grasslands or puna in the high Andes up to 3,400 m. (43 Olrog, C. C. (1956). Un águila nueva para la Argentina. Hornero 10:172–173. Close , 44 Olrog, C. C. (1985). Status of wet forest raptors in northern Argentina. In Conservation Studies on Raptors (I. Newton and R. D. Chancellor, Editors), International Council for Bird Preservation, Cambridge, UK. pp. 191–197 Close , 45 Esteban, J. G. (1959). Nuevo hallazgo del Águila Crestada de Des Murs. Acta Zoológica Lilloana 17:499–502. Close , 46 De Lucca, E. R. (1991). Rapaces amenazadas: El Águila Poma y el Águila Solitaria, estado de conocimiento actual. Nuestras Aves 25:14–15 Close , 47 Canevari, M., P. Canevari, B. R. Carrizo, G. Harris, J. R. Mata, and R. J. Straneck (1991). Nueva Guía de las Aves Argentinas. Volumes 1–2. Fundación Acindar, Buenos Aires, Argentina. Close , 33 Roesler, I., A. E. Formoso, F. N. Moschione, M. A. Juhant, and D. H. Podestá (2008). Nuevos registros del Águila Poma (Spizaetus isidori) y comentarios sobre su conservación en Argentina. Ornitología Neotropical 19(4):611–616. Close , 32 Fra, E. A., R. S. Salinas, P. Román-Rodríguez, and C. Barrionuevo (2008). Presencia y hábitat del Águila poma (Oroaetus isidori Des Murs, 1845) en la provincia de Catamarca, República Argentina. Revista Nuestras Aves 53:6-9. Close ).

Nests have only been reported between 1,300 and 2,900 m, mainly in old-growth montane forest, occasionally in emergent mature trees surrounded by secondary forest (resulting from previous human-made deforestation), and many of them relatively close to human-modified areas (14 Lehmann, F. C. (1959). Contribuciones al estudio de la fauna de Colombia XIV. Nuevas observaciones sobre Oroaetus isidori (Des Murs). Novedades Colombianas 1:169–195. Close , 48 Zuluaga, S., and M. Á. Echeverry‐Galvis (2016). Domestic fowl in the diet of the Black‐and‐chestnut Eagle (Spizaetus isidori) in the eastern Andes of Colombia: a potential conflict with humans? Ornitología Neotropical 27(1):113–120. Close , 40 Zuluaga, S., J. M. Grande, D. F. Aristizábal, and G. Guevara (2018). Parental dependence of a juvenile Black-and-chestnut Eagle (Spizaetus isidori) in the eastern Andes, Colombia. Ornitología Neotropical 29:153–158. Close , 37 Aráoz, R., J. M. Grande, C. López, J. Cereghetti, and F. H. Vargas (2017). The first Black-and-Chestnut Eagle (Spizaetus isidori) nest discovered in Argentina reveals potential human-predator conflicts. Journal of Raptor Research 51(1):79–82. Close , 49 Restrepo-Cardona, J. S., C. Márquez, M. A. Echeverry-Galvis, F. H. Vargas, D. M. Sánchez-Bellaizá, and L. M. Renjifo (2019). Deforestation may trigger Black-and-chestnut Eagle (Spizaetus isidori) predation on domestic fowl. Tropical Conservation Science 12:1-10. Close , TRF, unpublished data). Lehmann (14 Lehmann, F. C. (1959). Contribuciones al estudio de la fauna de Colombia XIV. Nuevas observaciones sobre Oroaetus isidori (Des Murs). Novedades Colombianas 1:169–195. Close ) indicated that some collected individuals came from a variety of habitats and elevational ranges from Venezuela and Colombia, and speculated that they were traveling between hunting areas. Juvenile eagles made their natal dispersal through fragmented landscapes, and they consistently selected areas with greater remaining forest cover, at mid elevations, and with steeper slopes than the mean available in the landscape (50 Zuluaga, S., F. H. Vargas, R. Aráoz, and J. M. Grande (2022). Main aerial top predator of the Andean Montane Forest copes with fragmentation, but may be paying a high cost. Global Ecology and Conservation 37(2022):e02174. Close ).