Red-billed Tyrannulet Zimmerius cinereicapilla


Justification of Red List Category

Based on a model of future deforestation in the Amazon basin it is suspected that the population of this species will decline rapidly over the next three generations, and it has therefore been uplisted to Vulnerable.

Population justification
The global population size has not been quantified, but this species is described as 'uncommon and patchily distributed' (Stotz et al. 1996).

Trend justification
This species is suspected to lose 33.7-34.4% of suitable habitat within its distribution over three generations (11 years) based on a model of Amazonian deforestation (Soares-Filho et al. 2006, Bird et al. 2011). It is therefore suspected to decline by ≥30% over three generations.

Distribution and population

Zimmerius cinereicapilla has a local distribution in the east Andean foothills (del Hoyo et al. 2004). It is very rare in Ecuador, known only from a single specimen taken in west Napo, a few observations in and around the Archidona Natural Reserve, and one reliable record from the Loja-Zamora road in the south-east (del Hoyo et al. 2004, Restall et al. 2006). In Peru it is more numerous, ranging from Amazonas, San Martín, Junín and Ayacucho south to Cuzco and Madre de Dios. Its distribution reaches La Paz department, north Bolivia, where sound recordings have been taken in Serranía de Establón (del Hoyo et al. 2004).


This is a species of humid montane and foothill forest, from 750-1,350 m. It prefers edges and openings, but also occurs in the interior. It generally remains in the canopy. Insects constitute the bulk of its diet, but it also feeds on fruits including those of the mistletoes (Loranthaceae) (del Hoyo et al. 2004).


The primary threat to this species is accelerating deforestation in the Amazon basin, with much of its range coming under pressure from logging, mining, agriculture and road building (del Hoyo et al. 2004, Soares-Filho et al. 2006, Bird et al. 2011).

Conservation actions

Conservation Actions Underway
None is known.

Conservation Actions Proposed

Expand the protected area network to effectively protect IBAs. Effectively resource and manage existing and new protected areas, utilising emerging opportunities to finance protected area management with the joint aims of reducing carbon emissions and maximizing biodiversity conservation. Conservation on private lands, through expanding market pressures for sound land management and preventing forest clearance on lands unsuitable for agriculture, is also essential (Soares-Filho et al. 2006).


10-11 cm. Large-headed green-and-yellow tyrannulet. Dark olive upperparts. Breast is a paler olive colour, fading into yellow on the belly. Grey forehead, crown and lores. Voice An ascending series, beginning with an emphatic note and ending with a wheet-wheet?.


Text account compilers
Butchart, S., Ekstrom, J., Khwaja, N., Symes, A., Sharpe, C J

Recommended citation
BirdLife International (2022) Species factsheet: Zimmerius cinereicapilla. Downloaded from on 07/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 07/07/2022.