BirdAnalyst
Species · Wyoming · BBS 2026 Release · 1966–2025

Vesper Sparrow Population Trend in Wyoming

All statesGrassland birds

Vesper Sparrow in Wyoming has increased: up 39% on the route-weighted index since 1970.

+39%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 →
138Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Vesper 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 Vesper Sparrow in Wyoming. See the full index history below.

Vesper Sparrow Population Forecast in Wyoming

If the recent trend holds, Vesper Sparrow in Wyoming is projected to stay roughly flat through 2030, near 20 (95% range 14–27). A 5-year backtest shows a typical error of ±12.6%, with 100% of held-out values landing inside the 95% band.

+7%Change by 2030TrendPercent 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 →
20Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
14–2795% 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 →
±12.6%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, Vesper Sparrow in Wyoming is projected to stay roughly flat through 2030, near 20 (95% range 14–27). A 5-year backtest shows a typical error of ±12.6%, with 100% of held-out values landing inside the 95% band.19682030
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 →
2026201326
2027201326
2028201327
2029201327
2030201427

Vesper Sparrow Survey Routes in Wyoming

Routes recording Vesper 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 →
Big Sandy7720251983
Leo7620251982
Sybille Cyn7620251980
Bairoil6820251988
Boulder6220251982
Seedskadee 26120242024
Arminto6020251982
Nowood5820251988
Meeteetse5820251998
Ryegrass5120251990
Rozet4920251991
Clark4720251990
Ne Entrance4620251982
Moran4420162002
Lamont4220251987
Frannie4120252000
Bucknum3820241993
Ervay3720251973
Shirley3620251980
Seely3520001990
Walcott3520251982
Crowheart3420211987
Gas Hills3120121991
Wyarno3020251974
Ethete3020251991

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsin

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.