BirdAnalyst
Species · Wyoming · BBS 2025 Release · 1966–2024

Brewer's Sparrow Population Trend in Wyoming

All statesGeneralists

Brewer's Sparrow in Wyoming has increased: up 46% on the route-weighted index since 1970.

+46%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 →
131Routes In StateSurvey 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 Brewer's Sparrow Trends in WyomingNotable 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 Wyoming. See the full index history below.

Brewer's Sparrow Population Forecast in Wyoming

If the recent trend holds, Brewer's Sparrow in Wyoming is projected to fall about 37% by 2029 — from 23 in 2024 to a central estimate of 15 (95% range 4.0–25). A 5-year backtest shows a typical error of ±23.5%, with 80% of held-out values landing inside the 95% band.

-37%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 →
15Projected 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 →
4.0–2595% 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 →
±23.5%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 Wyoming is projected to fall about 37% by 2029 — from 23 in 2024 to a central estimate of 15 (95% range 4.0–25). A 5-year backtest shows a typical error of ±23.5%, with 80% 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 →
2025154.125
2026154.125
2027154.025
2028154.025
2029154.025

Brewer's Sparrow Survey Routes in Wyoming

Routes recording Brewer's Sparrow in Wyoming.
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 →
Black Rock 214020242010
Seedskadee 212620242024
Bear Creek11520241968
Ryegrass11020241994
Rawlins 210920242015
Meeteetse9420241992
Mckinnon8619861969
Baggs8220241995
Bairoil8020241988
Bucknum7720241993
Patrick Draw6319801973
Reliance6320181977
Lamont6220241987
Diamondville6019821977
Flamin Gorge6020241988
Mtn View5920241980
Elk Horn 25820242022
Moran5120162002
Daniel4919881980
Ne Entrance4820211982
Colter Bay 24820242019
Frannie4720242000
Pathfinder4720241982
Nowood4320241988
Patrick Draw 54320092004

Brewer's Sparrow Population Trend in Other States

arizonacaliforniacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashington

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