EN
Crowned Solitary Eagle Buteogallus coronatus



Justification

Justification of Red List category
This species qualifies as Endangered because it has a very small, fragmented population, and the severity of the threats it faces strongly suggest a significant and continuing decline in numbers.

Population justification
The total population is placed in the band 250-999 mature individuals, equating to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend justification
A moderate and on-going population decline is suspected to be taking place on the basis of rates of hunting, habitat loss and persecution.

Distribution and population

Buteogallus coronatus has a very large range in Brazil (from Maranhão and Bahia west to Mato Grosso and south to Rio Grande do Sul), Bolivia (Beni and Santa Cruz), Paraguay (has been recorded throughout), and Argentina (Jujuy to south Buenos Aires, Rio Negro and La Pampa with an accidental record in Neuquén [Giai 1952, Gonnet and Blendinger 1998, Delhey and Carrete 1999], and an 1879 record from Chubut [R. Pereyra in litt. 2012]). There are no unequivocal records in Uruguay (Azpiroz and Cortés 2014). Trends are difficult to detect in low density populations but, given the severity of threats, it seems likely that a significant loss of numbers is occurring. In Paraguay it appears to be most numerous in the Cerrado of Concepción department; it also continues to be recorded in humid Chaco habitat with a new record in Ñeembucú department and there are records,  including juvenile birds, from sites in dry Chaco (H. del Castillo in litt. 2012).

Ecology

It inhabits lowland areas of semi-open seasonal dry country (palm-savanna, sparse woodland, steppes with bushes), chaco and campo cerrado (from campo limpo to cerrado sensu stricto). It sometimes occurs in moderate altitude hill-ranges in south-east Brazil and Argentina and has also been reported in caatinga, gallery forest, marsh and buriti groves. In Paraguay there are a number of recent records from extensive cattle ranches (H. del Castillo in litt. 2007). Reported foods include mammals, birds, reptiles, carrion and fish (R. P. Clay in litt. 2000), but in La Pampa, Argentina, armadillos and snakes and were the most important prey (Sarasola et al. 2010). A large platform nest is situated in trees or ravines and one egg is laid. Its movements are poorly understood, and it may be partially crepuscular.

Threats

Habitat destruction and hunting are the most pertinent threats. In Brazil, campo cerrado habitats are being rapidly destroyed by mechanised agriculture, intensive cattle-ranching, afforestation, invasive grasses, excessive use of pesticides and annual burning (Stotz et al. 1996, Parker and Willis 1997). The situation is similar in much of Paraguay, but habitat remains fairly intact in Concepción, where direct persecution is probably more significant. Chaco habitats are more intact, but increasing colonisation is destroying wooded areas and grassland. Persecution, including shooting and deliberate disturbance, may be a significant threat in central Argentina (Sarasola and Maceda 2006, Sarasola et al. 2010, R. Pereyra in litt. 2012): in La Pampa province at least 40 individuals are known to have been killed (R. Pereyra in litt. 2012). Recent records from Paraguay indicate that the species may be able to use extensive cattle ranches where it is not subjected to disturbance (H. del Castillo in litt. 2007). Collision with powerlines and drowning in water tanks are an unquantified cause of mortality in Argentina (R. Pereyra in litt. 2012). At least a dozen individuals have been recorded in illegal trade in Argentina (R. Pereyra in litt. 2012).

Conservation actions

Conservation Actions Underway
CITES Appendix II. It is protected in Argentina and Paraguay (H. del Castillo in litt. 2007), and hunting is prohibited in Brazil and Paraguay. There are few records from protected areas, but it has been found in more than a dozen protected areas in Argentina (R. Pereyra in litt. 2012), and small populations probably exist in Chapada dos Veadeiros (Wege and Long 1995), Emas, Brasília, Serra da Canastra (Silveira 1998) and Chapada dos Guimarães (L. F. Silveira in litt. 1999) National Parks, Brazil, and Beni Biological Station, Bolivia.

Conservation Actions Proposed
Survey to identify key populations, especially in the large Brazilian national parks. Study ecological constraints, breeding success and migration/dispersal patterns, possibly using satellite tracking. Enforce legal protection of the species. Organise awareness campaigns to limit hunting near key populations. Organise educational campaigns in areas where persecution is a threat (such as Central Argentina). Promote establishment of ecological corridors in southern Brazil to reduce effects of fragmentation. Establish protected areas in the dry Chaco (H. del Castillo in litt. 2012). Assess of other causes of mortality such as poisoning, electrocution with powerlines (J. H. Sarasola in litt. 2012) and drowning.

Identification

75-85 cm. Large, powerful, crested eagle. Long, broad wings with short tail. Dull slaty-grey, slightly darker on wings. Prominent bushy crest. Dusky tail with white band and tip. Yellowish legs and cere. Immature brown above with creamy head and dark post-ocular stripe. Cream throat and underparts, mottled brown on upper breast. Brown tarsi and mottling in lower belly. Similar spp. Great Black-hawk Buteogallus urubitinga lacks crest, is smaller and shorter-winged. Adult blacker, immature more heavily streaked brown below. Voice Powerful, long high-pitched whistle.

Acknowledgements

Text account compilers
Benstead, P., Capper, D., Mazar Barnett, J., Sharpe, C J & Symes, A.

Contributors
Baumgarten, L., Clay, R., De Luca, A., Develey, P., Silveira, L., del Castillo, H., Galmes, M., Pereyra , R. & Sarasola , J.


Recommended citation
BirdLife International (2023) Species factsheet: Buteogallus coronatus. Downloaded from http://datazone.birdlife.org/species/factsheet/crowned-solitary-eagle-buteogallus-coronatus on 04/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://datazone.birdlife.org on 04/12/2023.