Recurve-billed Bushbird (Clytoctantes alixii)

Recurve-billed Bushbird Clytoctantes alixii

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Justification

Justification of Red List category
This species has been recently rediscovered in both Venezuela and Colombia, following 40 years without any records. Its range and population are poorly known, but may be small. The species is therefore classified as Endangered.

Population justification
Based on the small number of birds recorded at the two known locations, e.g. with 6-7 pairs heard along a 2 km stretch of road at Ocaña (O. Laverde in litt. 2006), the total is probably best placed precautionarily in the band 250-999 individuals. This equates to 167-666 mature individuals, rounded here to 150-700 mature individuals. Further surveys may however show that the population is larger.

Trend justification
The species is suspected to undergo a slow decline due to habitat loss (Renjifo et al. 2016).

Distribution and population

Clytoctantes alixii is known only from extreme north-west Venezuela and north Colombia. Known historical localities are the Sierra de Perijá, Zulia, Venezuela, and in Colombia, the foothills of the Magdalena valley: in Santander and Cesar (north-east); the Serranía de San Lucas, Bolívar (north-west); Caldas (south-west); and four foothill sites north of the Andes in Antioquia and Córdoba. It was known from specimens taken between the 19^th century and the 1950s, but following sightings in 1965 in the Serranía de Abibe there were no further reports until its rediscovery in Venezuela in 2004 (Sharpe and Lentino 2015). The security risk posed by paramilitary groups and narcotics traffickers, together with the species's inconspicuousness and the lack of knowledge of its voice hindered rediscovery of a species which, judging by the large series of museum specimens and the scatter of reports from a fairly wide area, was once fairly common. It was finally refound in April 2004 in the Sierra de Perijá, Venezuela (C. J. Sharpe in litt. 2006). Shortly afterwards, in 2005 it was rediscovered in Colombia, at Ocaña, Norte de Santander (O. Laverde in litt. 2006). Here it appeared to be fairly common (6-7 pairs heard along a 2 km stretch of road) between 1,600 m and 1,750 m, much higher than previous records (O. Laverde in litt. 2006). In 2007 it was found above San Vicente de Chucuri in the Serranía de los Yariguíes, Santander (D. Willis in litt. 2007) and in Antiquoia (R. Clay in litt. 2007, Colorado 2008); in 2010 it was refound in the Serranía de San Lucas (Donegan 2012) and in 2016 in the Serranía de Abibe (Olaciregui et al. 2016). The southernmost record is from Eastern Caldas (Gil-Ospina and Moreno-López 2020). The species may well turn out to be more common and widespread than previously thought, especially as it appears to favour areas of secondary growth (C. J. Sharpe in litt. 2011, Renjifo et al. 2016).

Ecology

It inhabits lowland and foothill forests (185-1,750 m), favouring dense undergrowth, thickets, forest borders, young secondary growth and successional forest (Renjifo et al. 2016, Gil-Ospina and Moreo-López 2020). In Venezuela it has been found in the dense understorey of secondary habitats such as old swidden plots (C. J. Sharpe in litt. 2007) and seems to favour steep slopes with high water runoff in decaying secondary woodland (D. Ascanio in litt. 2007). The observations at Ocaña were in mature secondary growth with a strong bamboo component between 1,600 m and 1,750 m (O. Laverde in litt. 2006), but in the Serranía de los Yariguíes it was observed in an overgrown boulder-strewn gulley with no bamboo (D. Willis in litt. 2007). In Antioquia, it has been found at 300-800m in second growth with a dense understorey (Colorado 2008). In the west, breeding occurs during April-May, but in Caldas the reproductive period may start already in January (Gil-Ospina and Moreno-López 2020). The Species feeds on insects obtained by pecking open hollow stems and branches (C. J. Sharpe in litt. 2006, D. Ascanio in litt. 2007, Gil-Ospina and Moreno-López 2020).

Threats

The lower Magdalena valley had largely been converted to agricultural land as early as the 18th century, and the middle portions were rapidly opened up, colonised, logged and farmed during the 1960s and 1970s, although regeneration is beginning following land abandonment in some foothill areas (Stiles et al. 1999). Similarly, the lower Cauca valley and foothill areas at the northern end of the West and Central Andes have long been deforested, although some extensive forests survive (Forero 1989). This includes Paramillo National Park, where human settlement and activity pre-dates creation of the park and continues to threaten the forest (P. G. W. Salaman in litt. 1999). The species had been not uncommon in the vast, pristine forest of the Serranía de San Lucas. However, a gold-rush began in 1996, and most of the eastern slopes have since been settled, logged and converted to agriculture and coca production (A. Cuervo in litt. 1999, L. Dávalos in litt. 1999, Donegan and Salaman 1999, P. G. W. Salaman in litt. 1999). In the Sierra de Perijá there has been severe deforestation below 2,000 m for cattle-ranching and narcotics cultivation (C. J. Sharpe in litt. 1995, 1997, 2000). However, if the species does in fact favour secondary growth then increased farming of middle elevations in the Sierra de Perijá, although detrimental to primary forest specialists, may in fact be creating more suitable habitat for the species (C. J. Sharpe in litt. 2007). For the Antioquia population, the major short-term threat is the proposed construction of the Pescadero-Ituango hydroelectric dam on the Cauca river. If approved, this project would flood most of the habitat in this area (Colorado 2008).

Conservation actions

Conservation Actions Underway
It is considered nationally Endangered in Colombia (Renjifo et al. 2016) and Venezuela (Sharpe and Lentino 2015). Several specimen localities are now within Paramillo (Antioquia and Córdoba) and Perijá (Zulia) National Parks. It occurs in the recently purchased ProAves Recurve-billed Bushbird Reserve at Agua de la Virgen and by the Cerulean Warbler Reserve in the Serranía de los Yariguíes.

Conservation Actions Proposed
Search for it using tapes of the song and calls, as well as mist-nets, targeting any areas of extensive, well-developed secondary growth at 150-1,750 m. Improve management of Sierra de Perijá National Park (Sharpe and Lentino 2015). Increase the area of suitable habitat that has protected status; the possibility of extending Sierra de Perijá National Park should be evaluated (Sharpe and Lentino 2015).

Identification

16.5 cm. Chunky, short-tailed antbird with bizarrely large, recurved bill. Very large, pale horn-bill laterally compressed with sharp-ridged culmen. Wedge-shaped lower mandible upturned. Large, strong feet and legs, with long, straight hindclaw. Concealed white interscapular patch. Male mainly slaty-grey, black lores, throat, and upper breast. Faintly dotted white wing-coverts. Female rufescent-brown, rufous-chestnut forehead, sides of head and sides of body. Dusky tail and wings. Voice A loud, mid-range whistling peeeuw peeeuw peeuw-pweet-pweet-pweet

Acknowledgements

Text account compilers
Hermes, C.

Contributors
Ascanio, D., Butchart, S., Clay, R.P., Cuervo, A., Dávalos, L., Isherwood, I., Laverde, O., Pople, R., Salaman, P.G.W., Sharpe, C.J., Sharpe, C J, Stuart, T., Symes, A. & Willis, D.

Recommended citation
BirdLife International (2024) Species factsheet: Recurve-billed Bushbird Clytoctantes alixii. Downloaded from https://datazone.birdlife.org/species/factsheet/recurve-billed-bushbird-clytoctantes-alixii on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/11/2024.