LC
Brewer's Sparrow Spizella breweri



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
2018 Least Concern
2016 Least Concern
2012 Least Concern
2009 Least Concern
2008 Least Concern
2007 Near Threatened
2004 Not Recognised
2000 Not Recognised
1994 Not Recognised
1988 Not Recognised
Species attributes

Migratory status full migrant Forest dependency Does not normally occur in forest
Land mass type Land-mass type - continent
Average mass 11 g
Distribution

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 3,910,000 medium
Extent of Occurrence non-breeding (km2) 2,370,000 medium
Number of locations -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 17000000 poor estimated 2019
Population trend Decreasing medium inferred -
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 - - -

Population justification: The global population is estimated to number 17 million mature individuals (Partners in Flight 2019).

Trend justification: The species has been undergoing a moderate decline at an average rate of 1.1% per year between 1970 and 2017 (Partners in Flight 2019). Short-term trends suggest that the population has declined by 21% over the past ten years (Pardieck et al. 2018). However, population size estimates fluctuate between years and the trend estimate is biased towards end point values; therefore it is here assumed that the overall rate of decline does not approach the threshold for Vulnerable.


Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Canada N Extant Yes
Mexico N Extant Yes Yes
USA N Extant Yes Yes Yes Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Mexico Nacimiento Río Sabinas-Sureste de la Sierra de Santa Rosa
Mexico Presa Venustiano Carranza
Mexico Presa el Tulillo
Mexico Cuatro Ciénegas
Mexico El Manantial
Mexico Janos - Nuevo Casas Grandes
Mexico Pradera de Tokio
Canada Kilpoola Lake Area
Canada Chopaka Customs

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Grassland Temperate major non-breeding
Shrubland Temperate major breeding
Altitude 0 - 2000 m Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Invasive and other problematic species, genes & diseases Invasive non-native/alien species/diseases - Bromus tectorum Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation
Natural system modifications Fire & fire suppression - Increase in fire frequency/intensity Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Stresses
Ecosystem degradation

Recommended citation
BirdLife International (2022) Species factsheet: Spizella breweri. Downloaded from http://www.birdlife.org on 26/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 26/06/2022.