Justification of Red List Category
This species qualifies as Vulnerable because it has a small and declining population. Its range is severely fragmented and contracting as a result of habitat destruction (Collar et al. 1992).
This species is described as rare and essentially unknown; its population is placed in the band 2,500-9,999 individuals. This equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals.
This species's population is suspected to be declining slowly, in line with rates of habitat loss within its range.
Grallaria alleni is known from the west slope of the Central Andes, and the Western Andes in Colombia, and both Andean slopes in north Ecuador. The nominate subspecies was collected near Salento, Quindío, in 1911, and has been recorded in nearby Ucumarí Regional Park, Risaralda, Colombia, several times during 1994-2000 (P. G. W. Salaman in litt. 1999, C. Downing verbally 2000, Krabbe and Coopmans 2000). The subspecies andaquiensis was described from a specimen taken on the west slope of the southern East Andes in Cueva de los Guácharos National Park, Huila, Colombia, in 1971. During the 1990s, the subspecies has been found at single sites in Napo and Cotopaxi (Freile and Chaves 2004) and at four sites in Pichincha, Ecuador (J. Lyons in litt. 1998, N. Krabbe in litt. 1998, Krabbe and Coopmans 2000). An unknown subspecies is present in the Western Andes of Colombia (López-Ordóñez et al. 2013). Suitable habitat covers an estimated 3,500 km2 in Ecuador (Krabbe et al. 1998), but it is unclear how much of this is occupied. Recent surveys in Ecuador found at least 4-6 territories along three 1 km transects (J. F. Freile in litt. 2004, 2008). There are several new localities where the species has been recorded in Ecuador, mostly concentrated on the western slopes of Pichincha province (J. F. Freile in litt. 2004, 2008), and the species has recently been discovered to be much commoner and more extensively distributed in Colombia than previously thought (F. G. Stiles in litt. 2005). The paucity of earlier records is most likely related to the fact that its vocalisations were unknown until recently.
It occurs in wet, mossy cloud-forest, usually at 1,800-2,500 m in ravines or on steep slopes (Krabbe and Coopmans 2000). It has been seen on the ground and perched up to 3 m in the understorey (Krabbe and Coopmans 2000). Nests with nestlings have been found in March and December (i.e. during the wet season) (Freile and Renjifo 2003, Greeney and Gelis 2006). Food items recorded being taken to the nest include earthworms and katydids (Greeney and Gelis 2006).
Since the 17th century, most if not all cloud-forest in the upper Magdalena valley (Stiles 1998) and the Central Andes, Colombia, has been logged, settled and converted for agricultural purposes. The west Andean slopes in Ecuador have also been altered and fragmented, particularly in Pichincha (Krabbe et al. 1998, J. F. Freile in litt. 2004, 2008). A large area of intact habitat still exists on Volcán Sumaco (Napo), but in 1990, the human population started growing rapidly. As a consequence, also the forests at altitudes higher than 1,000 m are now being cleared for agriculture. Cueva de los Guácharos is increasingly threatened by encroaching human settlement and opium production (Wege and Long 1995). However, the species has been shown to use secondary forest freely within parts of its Colombian range and it was found in mature secondary forest on the Cotopaxi (J. F. Freile in litt. 2004, 2008, F. G. Stiles in litt. 2005). More extensive and well-protected forest remains in the eastern Andes, but records of the species there are still sparse (Freile et al. 2010).
Conservation Actions Underway
Subspecies G. a. andaquiensis is known from Maquipucuna Reserve (Pichincha), Mindo Protected Forest, Rio Guajalito, Cofán-Bermejo and La Otonga Reserves, and Cueva de los Guácharos and possibly Sumaco-Napo Galeras National Park (Krabbe and Coopmans 2000, J. F. Freile in litt. 2004, 2008, Freile et al. 2010). The recently created Sumaco-Napo Galeras National Park should prevent habitat loss from reaching the altitudes inhabited by the species in Napo. Ucumarí Regional Park holds a population of the nominate subspecies and it may occur in the adjacent Otún-Quimbaya Fauna and Flora Sanctuary and Alto Quindío Acaime Natural Reserve, both in Quindío (Krabbe and Coopmans 2000). On the east slope of the Andes in Ecuador its range is fairly well covered (c. 60%) by five protected areas (Cofan-Bermejo, Cayambe-Coca and Antisana Ecological Reserves, and Sumaco-Napo Galeras and Llanganates National Parks) (J. F. Freile in litt. 2004, 2008, Freile et al. 2010).
18 cm. Medium to large antpitta with white malar stripe. Dark rufescent-brown above. Slaty-grey crown and nape. Dark brown sides of head. Broad, white malar narrowly scaled black. Russet throat bordered by white chest-band. Olive-brown breast with few narrow white streaks. Buffy-white belly. Cinnamon washed flanks and undertail-coverts. Similar spp. Scaled Antpitta G. guatimalensis has black-scaled crown and upperparts. Voice Rapid series of c.22 deep, hollow huu whistles over 2.5-3 seconds, rapidly increasing in amplitude, then trailing off at end.
Text account compilers
Williams, R., Hardcastle, J., Hermes, C., Isherwood, I., Sharpe, C.J., Stuart, T., Symes, A., Benstead, P., Westrip, J.
Lyons, J., Krabbe, N., Stiles, F., Freile, J., Salaman, P., Greeney, H., Downing, C.
BirdLife International (2021) Species factsheet: Grallaria alleni. Downloaded from http://www.birdlife.org on 27/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 27/10/2021.