Cassin's Vireo (Vireo cassinii) - BirdLife species factsheet

Cassin's Vireo Vireo cassinii

Current view: Data table and detailed info

Taxonomy

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.

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	15 g

Range

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	2,430,000 km²	medium
Extent of Occurrence (non-breeding)	1,760,000 km²	medium
Severely fragmented?	no	-

Population

	Estimate	Data quality	Derivation	Year of estimate
Population size	5000000 mature individuals	poor	estimated	2019
Population trend	stable	-	estimated	-
Generation length	2.67 years	-	-	-

Population justification: The global population is estimated to number 5 million mature individuals (Partners in Flight 2019).

Trend justification: The species has been increasing at an average rate of 1.1% per year between 1970 and 2017 (Partners in Flight 2019). Short-term trends however suggest that the population has been roughly stable over the past ten years (Pardieck et al. 2018).

Country/territory distribution

Country/Territory	Presence	Origin	Breeding visitor	Non-breeding visitor	Passage migrant
Canada	extant	native	yes
Mexico	extant	native	yes	yes	yes
USA	extant	native	yes	yes	yes

Important Bird and Biodiversity Areas (IBA)

Country/Territory	IBA Name

Habitats & altitude

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Boreal	suitable	breeding
Forest	Subtropical/Tropical Dry	suitable	non-breeding
Forest	Subtropical/Tropical Dry	suitable	breeding
Forest	Subtropical/Tropical Moist Lowland	suitable	non-breeding
Forest	Subtropical/Tropical Moist Montane	suitable	non-breeding
Forest	Subtropical/Tropical Moist Montane	suitable	breeding
Forest	Temperate	major	breeding
Altitude	500 - 3000 m	Occasional altitudinal limits

Recommended citation
BirdLife International (2024) Species factsheet: Cassin's Vireo Vireo cassinii. Downloaded from https://datazone.birdlife.org/species/factsheet/cassins-vireo-vireo-cassinii on 23/11/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/11/2024.