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

Sounds and Vocal Behavior


Even by the standards of Neotropical raptors a relatively unvocal species. Most commonly heard in the vicinity of occupied nests, though lucky observers may also witness the rarely-recorded Flight Series, likely given during aerial displays. More work is needed on nearly every aspect of the Vocal Behavior of this species.


Vocal Array

Wail. The lowest-pitched call of the species is a nasal, overslurred wailing note, lasting between ca 0.5-1s. The overall quality of this call is reminiscent of some sounds from a Larus gull or a Limpkin (Aramus guarauna), and a bit lower-pitched than the calls of most other large raptors in range.

Alarm call. Notably higher-pitched than the Wail call, a relatively even-pitched series of long, clear to nasal notes starting with a voice break and continuing with a piercing quality. Most often heard from females near occupied nests.

Flight series. Poorly know but presumably similar to the flight series of other raptors, a stuttered series of relatively short, evenly-pitched notes at about the same frequency as the Wail call. Notable variation in the few available recordings, and more study needed to determine range of variability and exact function.

Juvenile calls. Chicks and juveniles develop typicalrepetitive tweet calls of other young eagles and hawks, which can sound similar to the Alarm Calls of adults as the birds get older.

Geographic Variation

None known but too few recordings available to properly assess.


Generally most vocal in the breeding season, and especially near the nest. At other times of year rarely heard, though juveniles especially can be vocal at any time of year.

Daily Pattern of Vocalizing

No information.

Places of Vocalizing

Alarm call most often heard from perched birds, especially near nests, but can also be uttered by birds in flight. Wail likewise heard during both flight and while perched, but perhaps most often heard from perched individuals, including when on or near nests. Flight Series solely uttered in flight, likely during displays (but more study needed). Juvenile Calls most common from perched birds.

Sex Differences

Little information other than that Alarm Calls most often heard from female birds.

Repertoire and Delivery of Songs

No information.

Social Context and Presumed Functions of Vocalizations

Flight Series may function as a display vocalization, but more study needed. Little information on other vocalizations other than Alarm Calls being indicative of some level of alarm due to proximity to occupied nests.

Nonvocal Sounds

Not recorded.

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