BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Brewer's Sparrow In Badlands and Prairies

All regionsBadlands and PrairiesGeneralists

Brewer's Sparrow in Badlands and Prairies has held roughly steady: down 7% on the route-weighted index since 1970.

-7%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
75Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Brewer's Sparrow in Badlands and Prairies. See the full index history below.

Brewer's Sparrow In Badlands and Prairies Population Forecast

If the recent trend holds, Brewer's Sparrow in Badlands and Prairies is projected to fall about 45% by 2029 — from 4.0 in 2024 to a central estimate of 2.2 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±26.8%, with 100% of held-out values landing inside the 95% band.

-45%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
2.2Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–4.995% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±26.8%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Brewer's Sparrow in Badlands and Prairies is projected to fall about 45% by 2029 — from 4.0 in 2024 to a central estimate of 2.2 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±26.8%, with 100% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20252.30.005.1
20262.30.005.0
20272.30.005.0
20282.20.005.0
20292.20.004.9

Routes In Badlands and Prairies

Routes recording Brewer's Sparrow in Badlands and Prairies.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
BucknumWYOMING772024
RavenWYOMING392024
CusterMONTANA372022
ShawneeWYOMING302024
ClarkelenWYOMING281978
Custer 2MONTANA242024
HighlightWYOMING212007
Caballa CrkWYOMING192021
PineyWYOMING181990
Teapot DomeWYOMING161989
SchoonoverWYOMING152024
UptonWYOMING152024
SussexWYOMING152024
WinnettMONTANA142023
BrandenbergMONTANA132019
Flatwillow 2MONTANA132023
RoundupMONTANA132024
GlenrockWYOMING131977
Two DotMONTANA102009
IngomarMONTANA102023
RozetWYOMING102023
NatronaWYOMING91992
BowmanNORTH-DAKOTA82009
HardingSOUTH-DAKOTA82017
SavagetonWYOMING82019

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.