Black-and-chestnut Eagle Spizaetus isidori Scientific name definitions

Tomás Rivas-Fuenzalida, Juan M. Grande, Sebastián Kohn, Felix Hernán Vargas, and Santiago Zuluaga Castañeda
Version: 2.0 — Published November 23, 2022

Movements and Migration


Little studied. Breeding adults are sedentary and their home range can exceed 3,000 ha (SZ and JMG, unpublished data). A juvenile during the post-fledging period remained near the nest, occupying an area of 48.1 ha, until it was independent (40). Six juveniles captured and tagged between 2015–2020 in Colombia and Argentina had large home ranges (mean ~1,000 km2) during their natal dispersal through fragmented landscapes (50). An immature tracked for four years (between 2015 and 2019) in eastern Colombia established its own territory when it was about three years old, approximately 20 km from its nest (SZ, unpublished data).

Dispersal and Site Fidelity

Natal Philopatry and Dispersal

Juveniles begin to disperse at around eight months old (40). During natal dispersal, the home range of immature birds can reach up to 200,000 ha, and juvenile birds can move up to 60 km from the nest (50). As young birds disperse, they may settle temporarily in an area where they spend several weeks to a few months before moving on to other areas. During this period, some juveniles may also visit their natal nest (notably when around one year old), from which they are expelled by the adults (Zuluaga et al., unpublished data).

Fidelity to Breeding Site

Nests are reportedly reused annually (14, 37, Rivas-Fuenzalida et al., unpublished data), but may also be abandoned after a season and then reused some years later (SK, unpublished data).

Recommended Citation

Rivas-Fuenzalida, T., J. M. Grande, S. Kohn, F. H. Vargas, and S. Zuluaga Castañeda (2022). Black-and-chestnut Eagle (Spizaetus isidori), version 2.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.baceag2.02