The crowned eagle (Buteogallus coronatus) is one of the great winged predators of South America. But today it survives almost as a living relic in the Southern Cone: it is endangered.
Experts estimate that there are between 800 and 2500 specimens worldwide, placing it in a critical situation. In Paraguay, for example, only 50 sightings have been documented in recent years.
The International Union for Conservation of Nature (IUCN) makes these estimates based on academic studies, field monitoring, and data provided by citizen science. However, the variability in the numbers reflects the lack of solid information about the species.
An emblematic case: Ekilore, the crowned eagle that crossed into Paraguay
The Center for the Study and Conservation of Birds of Prey in Argentina (CECARA) recently documented a key case, that of Ekilore, a specimen born in Santa Fe. Equipped with a GPS satellite transmitter, as reported by the site cienciasdelsur, it covered over 700 kilometers in less than a month.
On June 3, 2025, it crossed the Pilcomayo River and entered Paraguay after departing from San Cristóbal on May 9.
The uncommonly fast and extensive displacement crossed the Argentine provinces of Chaco and Formosa. This demonstrates the movement capacity of the species, although it does not undertake regular seasonal migrations.
Research and conservation: the Chaco Eagle Project
One of the main references in the research of this species is Diego Gallego García, a Basque biologist, with a master’s degree in zoology from the Complutense University of Madrid and currently a doctoral student at the National University of Comahue.
Gallego leads the Chaco Eagle Project, which combines science, conservation, and environmental education to protect this endangered raptor.
His work is supported by international scholarships and funds (CONICET, Smithsonian-Mason, The Rufford Foundation, among others), and with experience in renowned institutions such as Hawk Mountain Sanctuary (USA) and CIBIO-InBIO (Portugal).
Regarding the species’ genetics, studies have only been conducted in the semi-arid zone of Argentina so far, without finding clear population differences.
However, the small sample sizes prevented reaching definitive conclusions. Currently, efforts are being made to expand research with samples from Brazil, Paraguay, and Bolivia to better understand the genetic diversity and connectivity of the crowned eagle throughout its distribution area.
The role of citizen science and satellite monitoring
The delicate situation of the bird. (Photo: Wikipedia).
The record of Ekilore’s crossing did not surprise specialists, as in the last five years, 50 records in eBird have been logged about the presence of the crowned eagle in Paraguay, thanks to the participation of observers on platforms like eBird and iNaturalist.
Satellite monitoring is carried out with PTT (Platform Transmitter Terminal) transmitters, manufactured by Microwave Telemetry, with a lifespan of 6 to 8 years. These solar-powered devices record location data every hour during the day, allowing constant monitoring through the ARGOS system.
The data is stored on the international platform Movebank, managed by the Max Planck Institute of Ornithology, which not only facilitates the analysis of movements but also the integration of environmental variables such as vegetation cover, human pressure, and landscape connectivity.
A species in danger
According to specialists, the crowned eagle faces an uncertain future. Its low population density, habitat fragmentation, and the lack of information about its biology hinder its conservation.
Without a joint effort between science, local communities, and governments, this iconic raptor of the Southern Cone could be lost forever, leaving the South American sky without one of its most majestic symbols.
