Justification of Red List Category
This species is Endangered because remaining populations are very small and, given continuing threats, declining. Further surveys may find this species to be more widespread than recent records suggest, but effective protection of known sites is required if its conservation status is genuinely to improve.
The population is thought to number 1,000-2,499 individuals, based on an estimate of 1,000 in late 1970s and more recent information that some areas such as El Triunfo may be secure and hold relatively high densities. The core of this biosphere reserve alone could hold a population of 2,475-3,685 birds, but the band of 1,000-2,499 individuals is precautionarily retained here. This estimate equates to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals. Population density estimates for El Triunfo are 2.6-5.2 individuals/km2 (González-García 1992, 1994), 4.5-7.1 individuals/km2 (Gomez de Silva et al. 1999) and 3.7 individuals/km2 (Abundis-Santamaría and González-García 2006), equivalent to a population of 2,475-3,685 birds for the core of the biosphere reserve (González-García 2005, SEMARNAT 2011). In Guatemala, at Volcán San Pedro the estimates are 10.5 individuals/km2 (Rivas Romero and Cóbar Carranza 2008) and for Sierra de las Minas the estimates are 1.6 individuals/km2 (Quiñonez 2010).
The population is suspected to be declining, in line with the clearance and degradation of cloud-forest within its range, estimated to be occurring at rates of ~4% per three generations (Tracewski et al. 2016). Due to potentially high levels of hunting and trapping, the rate of population decline is tentatively placed in the band 20-29% over three generations.
Oreophasis derbianus occurs in the Sierra Madre de Chiapas, Mexico, and throughout west-central Guatemala. In Mexico, there are recent records from El Triunfo, Cerro Venado, Cerro Cebu, Cerro Quetzal and Volcán Tacaná (Cerro Toquián Grande, Chiquihuite, Agua Caliente, Benito Juárez El Plan), and birds have been purportedly collected, and a tail feather found, in the Chimalapas area of Oaxaca (J. Estudillo López in litt. 1994, González-García 1997, F. González-García in litt. 2012). Its occurrence in the Chimalapas, Oaxaca zone, has always been suspected, but never completely confirmed (F. González-García in litt. 2007). Fieldwork in 2005 and interviews with local people at San Antonio and Benito Juarez in the municipalities of San Miguel and Santa María, Chimalapas, suggest the presence of the species (F. González-García in litt. 2007). Verbal evidence suggests the Horned Guan is present in the areas known as Cordón El Retén y Sierra Tres Picos (González-García and Santana Castellón 2006). In Guatemala, it has been reported in at least 39 localities and its range has been estimated at 1,139.4 km2 (Rivas Romero and Cóbar Carranza 2007). The most recent Guatemalan records are from Cerro Cruz Maltín, Huehuetenango (Cotí 2010) and Chuamazán, Totonicapán (J. L. López per A. J. Cobar in litt. 2012). It was found nesting at Volcán Atitlán in 2005, 2007 and 2011 (Eisermann et al. 2007, Eisermann in litt. 2012) and at Volcan Tolimán in 2000 (Méndez 2010). In September 2007, two juveniles were observed at Volcán San Pedro, and in August 2009, another two juveniles were observed in Albores, Sierra de las Minas, confirming breeding at both sites (J. Rivas in litt. 2007, Quiñonez 2010). Fieldwork and interviews have recently identified new localities, including San Marcos and Sibinal in San Marcos department, and Chiantla and Santa Eulalia in Huehuetenango department (Cóbar Carranza and Rivas Romero 2006). Local people report the species from Cerro Tecpán, Chimaltenango, and Cerro El Amay, Quiché (K. Eisermann in litt. 2007), although specific surveys at the latter in 2008, 2010 and 2011 failed to find the species (Tanimoto 2008, P. Tanimoto in litt. 2008, Eisermann and Avendaño 2011, González Madrid 2011, K. Eisermann in litt. 2012). There are unconfirmed reports from Cerro Volcán Pacayita, Honduras. Unsuccessful searches for the species and interviews with local people in El Trifinio protected area suggest it is absent from this region and does not occur in Honduras (J. Rivas in litt. 2007). Numbers decreased severely during the 20th century and nowhere is it better than uncommon.
It inhabits cloud-forest at 2,000-3,500 m in Guatemala, with exceptional low-elevation records down to 1,200-1,500 m (Escobar-Ortíz 1997, K. Eisermann in litt. 2012), and 1,400-2,700 m in Mexico. The lack of records from June-August at El Triunfo suggests that it may undertake some altitudinal migration (Gómez de Silva et al. 1999). Breeding generally occurs in January-June, when two eggs are laid (González-García 1995). At Volcán Atitlán, a bird was found incubating in January 2005 on a nest that was apparently later predated, however an adult and immature were seen together there in November 2005 and January 2006. In November 2005, the immature bird was aged at 6-7 months, suggesting that hatching took place between early April and early May (Eisermann et al. 2007). At Volcán Tolimán two nests were found in March and April (Méndez 2010). Its diet comprises fruit, flowers and leaves (González-García 1994, 2005, Cóbar Carranza 2006, F. González-García in litt. 2007, Quiñonez 2010, González-García et al. 2017) and rarely invertebrates (González-García 1994).
Since the 1960s, logging, firewood-gathering and agricultural expansion have caused extensive deforestation. Forest is presently threatened by clearance for subsistence agriculture, coffee plantations, selective logging and wood extraction (J. Rivas in litt. 2007). In 2009 a forest fire affected more than 330 hectares of cloud forest in Volcán Santo Tomás (A. J. Cóbar in litt. 2012) and forest fires are now considered a considerable threat to its forest habitat (Brooks 2006). The loss and degradation of cloud-forest has caused the disappearance of the species from Cuilco, San Sebastian Coatan and the municipal area of San Pedro Soloma, in Guatemala (Cóbar Carranza and Rivas Romero 2006). Areas of forest have been cleared for agriculture in the core and buffer zones of El Triunfo Biosphere Reserve (V. Emanuel per Streiffert 2004, F. González-García in litt. 2012). Forest patches along the Zunil-Retalhuleu road, Guatemala, may be threatened, as they fall within the optimum altitudinal band for coffee-growing (Brooks and Gee 2006). If it is an altitudinal migrant, it will have especially suffered from the replacement of lower montane forests with sun coffee. New roads are opening up areas for exploitation. Disturbance and forest degradation may be caused by roaming cattle (Andrle undated). Hunting is mostly for subsistence (González-García 1993, F. González-García in litt. 1998, 1999): live birds are no longer taken for trade and private collections (J. Cornejo in litt. 2012). The isolation of disjunct subpopulations makes this species especially vulnerable to further local extirpation (K. Eisermann in litt. 2012). Climate change is further expected to exacerbate horned guan population declines by inducing shifts in the species' already restricted range (Sekercioglu et al. 2012).
Conservation Actions Underway
CITES Appendix I and legally protected in Mexico and Guatemala. In 2010 Mexico named the Horned Guan a one of the Conservation Priority Species (SEMARNAT 2011). An detailed conservation action plan for the species has been drawn up by the Mexican federal government (SEMARNAT 2011). An environmental education programme around El Triunfo has been in progress since 2010 (F. González-García in litt. 2012). The issues covered include strengthening local participation actions in the conservation of the Horned Guan, pasture management for local cattle ranchers and sustainable harvesting of dwarf 'shate' palm (F. González-García in litt. 2012). Another project at El Triunfo is concerned with the production of shade-grown coffee. Many coffee farmers are signing up for organic certification, with almost 121.4 km2 (30,000 acres) within the reserve certified by 2004 (Streiffert 2004). In Guatemala, most sites with recent records have protected status (K. Eisermann in litt. 2007). However, deficiencies in management that allow illegal hunting and illegal logging within protected areas are a serious issue for the species's conservation (K. Eisermann in litt. 2007). It has also been stated that there may not be enough suitable habitat incorporated in the national system of protected areas in Guatemala to ensure its survival in these reserves (Cóbar Carranza and Rivas Romero 2006). In Guatemala, communities at Sibinal, San Marcos (Department of San Marcos) and Tecpán (Department of Chimaltenango), at known sites for the species, have formally designated their forests as Municipal Protected Areas (A. J. Cóbar Carranza in litt. 2007), and at least one of these has a reforestation programme. In Guatemala, Cerro Yaxcalamte, Cerro Cruz Maltín, Municipal Forest of San Marcos and Volcán de Tajumulco have been identified as potential areas for further studies and conservation measures (Cóbar Carranza and Rivas Romero 2006). Horned Guan is a 'flagship species' for the development of local tourism at several sites in Guatemala, fostering local interest and initiatives to protect guan habitat, at Atitlán volcano, San Pedro volcano, and in Sibinal (K. Eisermann in litt. 2007, 2012). In 2002 a Population and Habitat Viability Analysis of the Horned Guan was held in Guatemala. This resulted in an action plan (CBSG 2002) and the establishment of the International Committee for the Conservation of Oreophasis derbianus and its Habitat, which is active in Mexico and Guatemala, and has organised four symposiums in which advances in conservation have been presented and the action plan reviewed (Secaira et al. 2006, J. Rivas in litt. 2007, J. Cornejo in litt. 2012). The Cloud Ambassadors Program was established in 2007 by Africam Safari to support in situ conservation efforts and create an international ex situ conservation network via the loaning of captive bred animals from Mexico (Cornejo 2008). The program manages a fund to support in situ conservation projects (J. Cornejo in litt. 2012). The captive husbandry of the species has improved in the last years (Cornejo 2008, 2009). According to the international studbook of the species, at the end of 2010 the captive population numbered 88 individuals, held by eleven institutions in six countries (J. Cornejo in litt. 2012).
84 cm. Unmistakable, large, black-and-white cracid. Glossy black above with bluish sheen. Whitish flecked black on neck, breast and upper belly with brown flanks and lower belly. Black tail with white band near base. Unusual red horn of bare skin on top of head and small red dewlap. White iris, yellow bill and red legs. Juvenile has reduced horn (develops through first year), and brown tail and wings. Voice Adult males and females differ in their vocalizations. Males utter four types, including a deep, low booming uhmm, uh'mmm uh'mmm, uh'mmm uh'mmm, uh'mmm uh'mmmmm. Females utter around 7-8 vocalisations and variants. Other vocalisations include snorts, clicking and bill-clacking (González-García 1995, 2001, Brooks and Gee 2006).
Text account compilers
Benstead, P., Capper, D., Cornejo, J., Cóbar Carranza, A., Eisermann, K., Estudillo López, J., González-García, F., Isherwood, I., Rivas, J., Sharpe, C.J., Tanimoto, P. & Taylor, J.
BirdLife International (2021) Species factsheet: Oreophasis derbianus. Downloaded from http://www.birdlife.org on 26/09/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/09/2021.