Justification of Red List Category
This species is known from a few sites in a region where the environment is highly modified and habitat degradation is apparently continuing (Collar et al. 1992). Its known population is extremely small and likely to be declining, and all subpopulations are smaller than 50 individuals. This combination of factors leads to its classification as Critically Endangered.
Surveys between 2004 and 2008 recorded 77 individuals. An approximate estimate based on these surveys and other records gives a total global population of 250 individuals (S. Valderrama in litt. 2010). However, until this is confirmed to be accurate, the population band of 50-249 individuals seems appropriate. This equates to 33-166 mature individuals, rounded here to 30-200 mature individuals.
The species is suspected to be in decline owing to the spread of agriculture near the type locality, and because of threats to its dry forest habitat, although the likely rate of decline has not been quantified.
Thryothorus nicefori occurs on the western slope of the East Andes in Colombia. The only known site was the type-locality at San Gil on the río Fonce south of Bucaramanga, where ten specimens were collected between 1944-1948 (Renjifo et al. 2002). There were no further records until two birds were observed and recorded in 1989, and then again in 2000 (Renjifo et al. 2002). Subsequently it has been recorded in Soata, Boyacá c. 100 km south and in the Yariguíes mountains 50 km to the west (Balchin 2007, Cortes et al. in press), and was then found in the municipalities of Curiti, Zapatoca, Barichara, Jordan, Galan, Socorro and Floridablanca, Santander (Parra et al. 2006). A 2008 survey in the department of Santander discovered a population of 21 individuals, which is now protected by the Niceforo's Wren Natural Bird Reserve. In addition it was recorded at Tipacoque, Susacon, Guacamayas, El Espino, Santa Rosa de Viterbo and Capitanejo (O. Cortes in litt. 2012). A further 56 individuals have been recorded in other regions, giving a known global population of 77. An approximate estimate places the population as high as 250 individuals, although its accuracy needs to be confirmed (S. Valderrama in litt. 2008, 2010).
The species occurs in dry forest habitat at 800-2,100 m, and its presence was found to be significantly correlated with that of Tricanthera gigantea, Acacia farnesiana, Sapindus saponaria and Pithecellobium dulce (O. Cortes in litt. 2007, 2012). It has also been recorded along the edges of shaded coffee and cacao plantations between 1,100 and 2,100 m (Valderrama et al. 2007a, O. Cortes in litt. 2012). All territories of individuals in the Santander population were located along water courses where vegetation is dense and perennial, and individuals were absent from areas devoid of a dense understorey due to grazing by goats (S. Valderrama in litt. 2008, 2010). Structural variables like abundance of lianas, trees and leaf litter are important components of the bird's habitat (Parra et al. 2010). It constructs an elongated nest in close association with wasps' nests (Valderrama et al. 2007a). Nests have been noted in hedges in agricultural lands (O. Cortes in litt. 2012).
This species is a habitat specialist, and its distribution is limited to Tricanthera spp and Pithecellobium dulce premontane forest along the River Chicamocha (O. Cortes in litt. 2012) . The greatest threat to the survival of this species is the destruction of these forests. The current threats to habitat in Chicamocha area are: cattle grazing, which has probably restricted the Tricanthera woodlands to steep slopes, inaccessible to cattle, and caused major fragmentation of the forest; burning for agriculture, which has caused a considerable reduction in the amount of vegetative cover; landslides; and firewood cutting, which has been one of the factors causing the destruction of the chicamocha forest in the past and present (O. Cortes in litt. 2012). Acacia scrub is threatened by goat- and cattle-grazing, seasonal burning for farming (P. G. W. Salaman in litt. 1999) and cutting for fuelwood (O. Cortes in litt. 2007, Cortes et al. in press). Areas grazed by goats near to the Santander population were devoid of the species due to a lack of dense understorey and leaf litter (S. Valderrama in litt. 2008, 2010).
Conservation and Research Actions Underway
It is considered Critically Endangered at the national level in Colombia (Renjifo et al. 2002). It is protected by the Yariguíes National Park (O. Cortes in litt. 2012). Project Chicamocha has been working for the conservation of Niceforo’s Wren since 2004 (M. Beltrán in litt. 2012). In 2009 Niceforo's Wren Natural Bird Reserve was established by Project Chicamocha in Zapatoca, Santander; run by Fundación ProAves, the reserve comprises 1,400 ha of the species's tropical dry forest habitat, protecting a population of 21 individuals discovered in Santander province in 2008 (M. Beltrán in litt. 2012). Project Chicamocha has subsequently been carrying out research on the effects of territory size and habitat quality in the physical condition of Niceforo’s Wren (Parra et al. 2010). Fundación Conserva is updating the geographical distribution and population size of Niceforo’s Wren and searching for new areas for its protection (M. Beltrán in litt. 2012). Surveys have been conducted to search for the species in a number of new areas, and more are planned for the future. In 2014 the Niceforo's Wren Natural Bird Reserve was registered as a natural reserve of the Civil Society and is now part of the National System of Protected Areas (ProAves 2014).
15 cm. Medium-sized, rufous-and-white wren. Olive-brown crown to upper back. Rest of upperparts rufous-brown giving two-toned appearance. Prominent white superciliary. Black barred tail and wings. Black-and-white streaked sides of head. White underparts with pale greyish-brown flanks and sides. Black barred crissum. Similar species Rufous-and-white Wren (T. rufalbus) has uniform bright rufous upperparts. Voice Similar to T. rufalbus. Several low-pitched, slow, mellow, bouncing whistles, preceded by higher notes.
Text account compilers
Bird, J., Calvert, R., Isherwood, I., Pople, R., Sharpe, C J, Stuart, T., Symes, A., Taylor, J. & Wright, L
Cortés, O., Salaman, P., Stiles, F., Valderrama, S. & Beltrán, M.
BirdLife International (2019) Species factsheet: Thryophilus nicefori. Downloaded from http://www.birdlife.org on 19/04/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/04/2019.