LC
Varied Thrush Ixoreus naevius



Taxonomy

Taxonomic source(s)
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: #http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls#.
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.

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

Red List history
Year Category Criteria
2021 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2004 Least Concern
2000 Lower Risk/Least Concern
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status full migrant Forest dependency High
Land mass type Average mass -
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 6,170,000 medium
Extent of Occurrence non-breeding (km2) 4,540,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 35000000 poor estimated 2019
Population trend Decreasing estimated -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) - - -
Decline (10 years/3 generation past and future) - - -
Number of subpopulations - - -
Percentage in largest subpopulation - - -
Generation length (yrs) 3.31 - - -

Population justification: The global population is estimated to number 35 million mature individuals (Partners in Flight 2019).

Trend justification: The species has been undergoing a large decline at an average rate of 2.2% per year between 1970 and 2017 (Partners in Flight 2019). The population however fluctuates depending on winter conditions and trends may vary locally (Meehan et al. 2018; Pardieck et al. 2018; George 2020).


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Bermuda (to UK) V Extant
Canada N Extant Yes Yes
Mexico N Extant Yes Yes
St Pierre and Miquelon (to France) V Extant
United Kingdom V Extant
USA N Extant Yes Yes Yes Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Canada Sumallo River/Skagit Valley

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Boreal major breeding
Forest Temperate major breeding
Forest Temperate major non-breeding
Altitude   Occasional altitudinal limits  

Recommended citation
BirdLife International (2022) Species factsheet: Ixoreus naevius. Downloaded from http://www.birdlife.org on 06/07/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 06/07/2022.