Justification of Red List Category
This species has a very small range and there are records from only two locations. Coca-growers have taken over forest within its altitudinal range, probably resulting in some reductions in this species's range and population. It is consequently classified as Endangered.
It has a very small range, and appears to be rather scarce. The population is estimated to number 1,000-2,499 individuals, equating to 667-1,333 mature individuals, rounded to 600-1,500 mature individuals here. This requires confirmation.
A slow and ongoing population decline is suspected owing to rates of habitat loss.
Aulacorhynchus huallagae is known from only two localities in north-central Peru. It is uncommon at the type-locality in La Libertad, and apparently very rare in Río Abiseo National Park, San Martín. It has also been reported recently from Leymebambe (T. Mark in litt. 2003). It is predicted to occur to the north and south, but little of the area between the Cordillera de Colán, Amazonas, and the Carpish region, Huánuco, is accessible (Schulenberg and Parker 1997). However, it does not appear to occupy all potentially available forest, since there are no records from the relatively well-surveyed Carpish Mountains (Schulenberg and Parker 1997).
It inhabits the canopy of humid, epiphyte-laden montane forest, particularly areas with Clusia trees (Fjeldså and Krabbe 1990), at elevations of 2,000-2,600 m (Schulenberg et al. 2007). This narrow altitudinal range has been explained by the occurrence of the larger Grey-breasted Mountain-toucan Andigena hypoglauca above 2,300 m, and perhaps the smaller Emerald Toucanet Aulacorhynchus prasinus below 2,100 m. However, its restricted geographic range remains unexplained, and more recent information indicates that both the putative competitors have wider altitudinal ranges that (at least in some areas) completely encompass the known elevational range of A. huallagae (Clements and Shany 2001; J. Hornbuckle in litt. 1999).
The Huallaga valley, especially the upper reaches, was being taken over by coca-growers in the early 1990s, and it seems likely that forest at all elevations has suffered (M. A. Plenge in litt. 1993). Deforestation has been widespread in the region, but mainly below this species's altitudinal range. In fact, the human population within its range was higher in the post than at present (T. Mark in litt. 2010).
Conservation Actions Underway
It occurs within the extensive Río Abiseo National Park, but the population in this reserve may be small.
37-41 cm. All-green toucanet with distinctive short yellow line behind eye and blue breast-band. Blue-grey bill with narrow white line at base and white throat. Central tail feathers tipped chestnut and yellow undertail-coverts. Similar spp. Other principally all-green toucanets have different bill patterns and lack yellow eyebrow. Voice A monotonously repeated short, dry rattling cuah cuah cuah. Approx. 2/sec.
Text account compilers
Benstead, P., Harding, M., Capper, D., Sharpe, C.J., Symes, A.
Hornbuckle, J., Mark, T. & Plenge, M.A.
BirdLife International (2020) Species factsheet: Aulacorhynchus huallagae. Downloaded from http://www.birdlife.org on 06/06/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/06/2020.