Mishana Tyrannulet Zimmerius villarejoi


Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.
SACC. 2005 and updates. A classification of the bird species of South America. Available at: #

IUCN Red List criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - -

Red List history
Year Category Criteria
2022 Least Concern
2016 Vulnerable C2a(ii)
2012 Vulnerable C2a(ii)
2008 Vulnerable C2a(ii)
2004 Vulnerable
2002 Vulnerable
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status not a migrant Forest dependency high
Land-mass type continent
Average mass 7 g

Estimate Data quality
Extent of Occurrence (breeding/resident) 127,500 km2 medium
Severely fragmented? no -
Estimate Data quality Derivation Year of estimate
Population size 10000-19999 mature individuals poor inferred 2020
Population trend decreasing poor suspected 2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the future 10 years/3 generations (longer of the two periods) 1-9% - - -
Rate of change over the past & future 10 years/3 generations (longer of the two periods) 1-9% - - -
Generation length 2.7 years - - -
Number of subpopulations 2 - - -
Percentage of mature individuals in largest subpopulation 1-89% - - -

Population justification: The species is considered uncommon (Álvarez et al. 2012). Based on the population density of a sympatric congener (Z. gracilipes in Peru: 4 mature individuals/km2; Santini et al. 2018) and assuming that only 10% of the range are occupied to account for the species's rarity, the global population may number c.12,000 mature individuals. To account for uncertainty, the population size is therefore here placed in the band 10,000-19,999 mature individuals.
The population forms two disconnected subpopulations in Loreto and in San Martín. Based on the range area and suspected density, both subpopulations may be of roughly equal size, numbering 5,000-9,999 mature individuals each.

Trend justification: The species is suspected to decline slowly due to the loss of its habitat. Over ten years, about 6-7% of tree cover is lost within the range (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). The species is forest-dependent; however, it appears to tolerate selective logging (Socolar 2020). Therefore, population declines are thought not to exceed 10% over ten years.

Country/territory distribution
Country/Territory Presence Origin Resident Breeding visitor Non-breeding visitor Passage migrant
Peru extant native yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Peru Cuenca Río Nanay
Peru Moyobamba

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Altitude 110 - 1100 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation, Ecosystem conversion

Recommended citation
BirdLife International (2024) Species factsheet: Zimmerius villarejoi. Downloaded from on 21/02/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from on 21/02/2024.