NT
Chestnut-backed Thornbird Phacellodomus dorsalis



Justification

Justification of Red List Category
This species occurs in a small range, in which habitat is lost at a low rate. Due to its tolerance of converted and degraded habitats, it is currently not considered at imminent risk. The species is therefore listed as Near Threatened.

Population justification
The population size is preliminarily estimated to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals. The species is described as uncommon (Fjeldså and Krabbe 1990, Ridgely and Tudor 1994, Clements and Shany 2001).

Trend justification
The population trend has not been estimated directly. The only threat known to the species is the loss and degradation of its habitat. Tree cover loss within the range has been low over ten years (< 2%; Global Forest Watch 2020). Given that the species does not depend on forest, but readily tolerates degraded and converted habitats, the rate of population decline is unlikely to exceed 10% over ten years.

Distribution and population

Phacellodomus dorsalis occurs on the east slope of the west Andes in the upper Marañón valley in south Cajamarca, Amazonas and La Libertad, north-west Peru (Fjeldså and Krabbe 1990, Ridgely and Tudor 1994, Clements and Shany 2001). It is known from at least five localities on the eastern and western sides of the Marañón valley (Angulo et al. 2008, F. Angulo in litt. 2020). There is also a sighting on the east slope of Cordillera Blanca in Ancash (Ridgely and Tudor 1994, R. Webster and R. A. Rowlett in litt. 1998). The species is generally considered uncommon (Fjeldså and Krabbe 1990, Ridgely and Tudor 1994, Clements and Shany 2001), but was found to be fairly common around Hacienda Limón in Cajamarca (R. Webster and R. A. Rowlett in litt. 1998).

Ecology

It is found in arid to fairly humid, dense, tangled thorn-scrub, pastures and hedgerows on bushy slopes with scattered Acacia macracantha trees (F. Angulo in litt. 2012). Most records are at elevations of 2,000-3,100 m (Fjeldså and Krabbe 1990, Ridgely and Tudor 1994, Schulenberg et al. 2007), but in the Cordillera Blanca it was recorded at 3,400 m (Ridgely and Tudor 1994). Around Hacienda Limón, it occurs in areas with substantial disturbance, including along dry streambeds and eroded gullies adjacent to agricultural areas (R. Webster and R. A. Rowlett in litt. 1998). Nests tend to be placed in A. macracantha trees and are made from twigs of the same tree (F. Angulo in litt. 2012).

Threats

Habitat in the Marañón drainage has deteriorated progressively under a prolonged period of cultivation. The species apparently tolerates some degree of habitat alteration, but whether it can complete its life-cycle or occur at existing densities in heavily cultivated areas is not known. Fire and clearance of land for agriculture are the principal threats (F. Angulo in litt. 2012).

Conservation actions

Conservation Actions Underway
None are known. Proposals for key sites to be protected are found in Angulo et al. (2008).

Conservation Actions Proposed
Survey to assess the species's distribution and population. Research its natural history, including basic information such as vocalisations. Ensure the protection of areas around Hacienda Limón. Establish at least one protected area within the species's range (F. Angulo in litt. 2012).

Identification

19 cm. Large, brown-and-rufous furnariid. Rufescent crown with pale streaking. Greyish-brown nape and upperparts. Rufous-chestnut back and mostly rufous wings and tail. Whitish underparts with rufous speckling on breast and rufous tinge on flanks. Immature has no rufous on crown. Similar spp. Common Thornbird P. rufifrons lacks rufous on back and breast. Voice Not reported. Hints Large cylindrical nests, typical of genus and usually placed near the tip of a tree branch, are more conspicuous than the species itself. Voice A series of short sharp descending accelerating squeaky calls

Acknowledgements

Text account compilers
Hermes, C.

Contributors
Angulo Pratolongo, F., Capper, D., Pople, R., Rowlett, R.A., Sharpe, C.J., Stuart, T., Symes, A. & Webster, R.


Recommended citation
BirdLife International (2021) Species factsheet: Phacellodomus dorsalis. Downloaded from http://www.birdlife.org on 04/12/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 04/12/2021.