Species

Justification
This species is classified as Vulnerable because it has a very small range and is known from just two locations. It is therefore highly susceptible to stochastic events, and may be increasingly threatened in the near future by potential human developments in the area.

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
SACC. 2006. A classification of the bird species of South America. Available at: http://www.museum.lsu.edu/~Remsen/SACCBaseline.html.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Stotz, D. F.; Fitzpatrick, J. W.; Parker, T. A.; Moskovits, D. K. 1996. Neotropical birds: ecology and conservation. University of Chicago Press, Chicago.

Identification
13.5 cm. Distinctively marked warbler. Dull olive-green upperparts, creamy-yellow underparts, greenish-yellow supercilium bordered by black above, rufous crown, dusky olive ear-coverts. Voice Song is undescribed. Call a penetrating tseeut.

Distribution and population
Basileuterus ignotus is confined to a very small range, estimated at c.180 km², on Alturas de Nique and Cerro Tacarcuna in Darién, Panama, and north-west Chocó, Colombia (Wetmore 1984, Ridgely and Gwynne 1989, Wege 1996). Within this range it is thought to occupy an area of less than 100 km² of suitable habitat (Wege 1996). It is generally uncommon (Ridgely and Gwynne 1989), but was found to be fairly common above 1,400 m on Alturas de Nique (above Cana) in 1985 (Robbins et al. 1985).

Population justification
The population is estimated to number 1,000-2,499 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.

Trend justification
There is no new information on population size or trends, and no evidence of any currently active threats to the population.

Ecology
It inhabits the lower growth of humid elfin forest, where it is mainly recorded between 1,350 and 1,650 m, but sometimes as low as 1,200 m (Ridgely and Gwynne 1989). The breeding behaviour is virtually unknown, but recently fledged young have been seen in July (Robbins et al. 1985).

Threats
Its small range puts it at inherent risk from any habitat loss or degradation. Habitat in the region is being cleared and degraded for mining, agriculture and cultivation of coca (Wege 1996), but probably not yet within the altitudinal range of this species. Completion of the Pan-American highway link through Darién could lead to severe, long-term damage of forests in Darién and the adjacent Chocó (Alvarez-Cordero et al. 1994, Wege 1996).

Conservation actions underway
The Panamanian part (i.e. the majority) of its range lies entirely within Darién National Park (Wege 1996). However, legal protection has not halted habitat loss at lower altitudes (Wege 1996). In Colombia, it may be found to occur within Katíos National Park (Renjifo et al. 2002).

Conservation actions proposed
Develop active conservation management schemes to control activities threatening birds in Darién (Wege 1996). Survey the Cerro Pirre area and Serranía de Tacarcuna (the Panamanian part has not been studied since the 1970s). Determine its status within Katíos National Park (Renjifo et al. 2002). Investigate the creation of a protected area in the Colombian sector of Cerro Tacarcuna (Renjifo et al. 2002).

References
Renjifo, L. M.; Franco-Maya, A. M.; Amaya-Espinel, J. D.; Kattan, G. H.; López-Lanús, B. 2002. Libro rojo de aves de Colombia. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt y Ministerio del Medio Ambiente, Bogotá, Colombia.

Wetmore, A.; Pasquier, R. F.; Olson, S. L. 1984. Birds of the Republic of Panamá. Smithsonian Institution Press, Washington, D.C.

Robbins, M. B.; Parker, T. A.; Allen, S. E. 1985. The avifauna of Cerro Pirre, Darién, eastern Panama. In: Buckley, P.A. (ed.), Neotropical Ornothology, pp. 198-232. American Ornithologist's Union, Washington D.C.

Ridgely, R. S.; Gwynne, J. A. 1989. A guide to the birds of Panama with Costa Rica, Nicaragua, and Honduras. Princeton University Press, Princeton.

Alvarez-Cordero, E.; de Samudio, J.; Marquez Reyes, C.; Ellis, S. 1994. Conservation assessment and management plan workshop for bird and mammal species endemic to Panama. International Union for Nature Conservation and Natural Resources, Apple Valley, MN.

Wege, D. C. 1996. Threatened birds of the Darién Highland, Panama: a reassessment. Bird Conservation International 6: 191-195.

Further web sources of information
Hear sounds for this species from xeno-canto, the community database of shared bird sounds from around the world.

View photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Bird, J., Butchart, S., Gilroy, J., Isherwood, I., Pople, R., Sharpe, C J, Stuart, T.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2013) Species factsheet: Basileuterus ignotus. Downloaded from http://www.birdlife.org on 24/05/2013. Recommended citation for factsheets for more than one species: BirdLife International (2013) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 24/05/2013.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Additional resources for this species

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