Justification of Red List Category
This species qualifies as Vulnerable because it is assumed to have a small population, which is fragmented and likely to be declining. However, further surveys may find the species at additional locations which, given its extensive range and apparent degree of habitat tolerance, could result in a downlisting to Near Threatened or Least Concern.
This species is poorly known. It appears to be very rare to rare and very local throughout its range. Collar et al. (1992) described it as exceedingly rare. Given this, the total population is estimated to fall below 10,000 individuals, despite its large range. It is placed in the band 2,500-9,999 individuals, equating to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals. Further information is required to validate this however.
Trends have not been well documented, but the species appears to be declining for poorly understood reasons (B. Knapton in litt. 2003), being scarce in areas even in areas where it was formerly described as relatively numerous (e.g. Ridgely and Tudor 1994). In Ecuador, there has been an apparently precipitous drop in numbers (Ridgely and Greenfield 2001). The situation in Peru is similar (Schulenberg et al. 2007).
Agriornis albicauda occurs in the high Andes from Ecuador to northern Chile and Argentina, but the population is small and probably declining. Subspecies andicola occurs in Ecuador (Imbabura, Pichincha, Napo, Chimborazo, Cañar, Zamora-Chinchipe and Loja provinces), and was found at four new sites in 1995-1999 (Krabbe et al. 1996, Howell and Webb in prep., J. Fjeldså in litt. 1999, N. Simpson in litt. 2000). The nominate subspecies albicauda occurs in Peru (Cajamarca, La Libertad, Huánuco, Ancash, Pasco, Cuzco, Lima, Arequipa and Ayacucho) with 16 records since 1952 (Clements 1998, N. Simpson in litt. 2000, Begazo et al. 2001, D. Geale in litt. 2005, M. Ugarte-Lewis in litt. 2005); Bolivia, where there are records from La Paz in 1941, Oruro in 1967 and 1991, Potosí in 1967, Chusquisaca in 1991 (Fjeldså and Mayer 1996) and Cochabamba in 1997 (Herzog et al. 1999); north Chile in Tarapacá and Antofagasta, with recent records from the precordillera and altiplanos of Arica (Howell and Webb 1995b, Howell and Webb in prep.), and north-west Argentina in Sierra de Aconquija and Tucumán, with one record from Catamarca in 1918 (Chebez 1994, Blendinger 1998, H. Povedano in litt. 1999).
It was thought to exclusively inhabit the páramo and puna zones, high above the treeline at 3,500-4,300 m. However, in south Ecuador, it has been found in semi-arid, bushy country, especially in areas with large Puyas, at 2,400-3,100 m (Krabbe et al. 1996). It favours open areas with sparse vegetation and scattered rocks, particularly near old buildings and walls (Ridgely and Tudor 1994, Vuilleumier 1994), and has been recorded from rocky Polylepis groves (Vuilleumier 1994). There are two records from open farmland with hedgerows and introduced Eucalyptus trees (Krabbe et al. 1996, N. Simpson in litt. 2000), one from agricultural land (crops and pasture) with introduced pine trees (M. Ugarte-Lewis in litt. 2005), and one from cactus scrub with Eucalyptus (B. Knapton in litt. 2003).
The reasons for this species's scarcity are unclear. Open (albeit modified) grassland habitats have been expanding for centuries owing to burning and grazing (Fjeldså and Kessler 1996, Kessler and Herzog 1998, T. S. Schulenberg in litt. 1999). It may historically have been out-competed by A. montana, and this may continue (B. Knapton in litt. 2003), although the two have coexisted for at least a million years (T. S. Schulenberg in litt. 1999). It could be unusually predator-prone (Krabbe et al. 1996). However, such threats provide unlikely explanations for the species's rarity.
Conservation Actions Underway
There are recent records from Huascarán National Park, Peru, and Lauca National Park, Chile.
25 cm. Large, greyish-brown tyrant. Dark greyish-brown above, darker on wings. Inconspicuous pale supercilium. White throat heavily streaked blackish. Pale grey-brown breast and flanks. Pale centre to belly. White tail except for dark greyish-brown central rectrices. Heavy, dark bill. Similar spp. Black-billed Shrike-tyrant A. montana is slightly smaller, with less conspicuous streaking on throat, and much thinner and less stout bill.
Text account compilers
Benstead, P., Capper, D., Harding, M., Mazar Barnett, J., O'Brien, A., Sharpe, C J, Symes, A., Temple, H., Khwaja, N.
Simpson, N., Krabbe, N., Schulenberg, T., Knapton, B., Povedano, H., Geale, D., Ugarte-Lewis, M., Fjeldså, J.
BirdLife International (2018) Species factsheet: Agriornis albicauda. Downloaded from http://www.birdlife.org on 12/12/2018. Recommended citation for factsheets for more than one species: BirdLife International (2018) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 12/12/2018.