Bachman's Sparrow Peucaea aestivalis


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
2018 Near Threatened A2ac+3c+4ac
2016 Near Threatened A2c
2012 Near Threatened A2c
2008 Near Threatened A2c
2004 Near Threatened
2000 Lower Risk/Near Threatened
1994 Lower Risk/Least Concern
1988 Lower Risk/Least Concern
Species attributes

Migratory status not a migrant Forest dependency Medium
Land mass type Land-mass type - continent
Average mass 19 g
Extent of occurrence (EOO)

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 1,650,000 medium
Extent of Occurrence non-breeding (km2) 1,150,000 medium
Number of locations -
Fragmentation -
Population and trend
Estimate Data quality Derivation Year of estimate
No. of mature individuals 190000 medium estimated 2016
Population trend Decreasing medium 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) 20-29 - - -
Decline (10 years/3 generation past and future) 20-29 - - -
Number of subpopulations - - -
Largest subpopulations - - -
Generation length (yrs) 3.7 - - -

Population justification: Rosenberg et al. (2016) estimate the population size at 190,000 mature individuals.

Trend justification: Data from the Breeding Bird Survey suggests that this species may have undergone a decline of c.3.6% per year between 2005 and 2015 (Sauer et al. 2017), which would equate to a decline of c.32.5% over 3 generations (c.11 years). However, there is uncertainty over this value, with the 95% CI for annual declines being c.5.6% to c.1.7% (Sauer et al. 2017). These would represent a decline over 3 generations of 47% and 16.9% respectively. Additionally, looking at data from between 2007 (three generations ago) and 2015, the decline is non-significant (annual decline of 2.7% [6.8% decrease to 1.4% increase], roughly equating to a reduction of 26.0% [54.1% decrease to 16.8% increase] over three generations) (Sauer et al. 2017). Data from the Christmas Bird Count (between 1966 and 2017) shows, on average, an annual decline of 2.6% (4.9% annual decline to 0.6% annual increase) in this species. This would equate to a reduction of 25.5% (43.0% reduction to 7.0% increase) over three generations (T. Meehan in litt. 2018). Partners in Flight have given this species a half-life of 24 years (Rosenberg et al. 2016), which would equate to a decline of 27.4% over 3 generations. Therefore, the decline has been tentatively placed in the range of 20-29%.

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

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
USA Kissimmee Prairie Preserve and State Park
USA St. Sebastian River State Buffer Preserve
USA Shortleaf Pine-Bluestem Grass Ecosystem Management Area
USA Ichetucknee Springs State Park
USA Myakka River Watershed
USA Wekiwa Basin GEOPark
USA Babcock-Webb Ecosystem
USA Sandhills West
USA Fort Chaffee

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Forest Subtropical/Tropical Dry major resident
Forest Temperate major resident
Shrubland Temperate suitable resident
Altitude 0 - 900 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
Human intrusions & disturbance Recreational activities Timing Scope Severity Impact
Ongoing Minority (<50%) No decline Low Impact: 4
Species disturbance
Natural system modifications Fire & fire suppression - Supression in fire frequency/intensity Timing Scope Severity Impact
Ongoing Majority (50-90%) Negligible declines Low Impact: 5
Ecosystem degradation
Residential & commercial development Housing & urban areas Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Transportation & service corridors Utility & service lines Timing Scope Severity Impact
Ongoing Minority (<50%) Negligible declines Low Impact: 4
Species mortality

Purpose Primary form used Life stage used Source Scale Level Timing
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2020) Species factsheet: Peucaea aestivalis. Downloaded from http://www.birdlife.org on 03/08/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 03/08/2020.