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

Grasshopper Sparrow Population Trend in Wyoming

All statesGrassland birds

Grasshopper Sparrow in Wyoming has risen sharply: up 63% on the route-weighted index since 1971.

+63%Since 1971TrendPercent 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 →
79Routes 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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Grasshopper 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Grasshopper Sparrow has risen sharply in Wyoming: up 63% on the route-weighted index since 1971.

Grasshopper Sparrow Population Forecast in Wyoming

If the recent trend holds, Grasshopper Sparrow in Wyoming is projected to stay roughly flat through 2029, near 2.6 (95% range 0.52–4.6). A 5-year backtest shows a typical error of ±71.9%, with 100% of held-out values landing inside the 95% band.

+4%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 →
2.6Projected 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 →
0.52–4.695% 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 →
±71.9%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, Grasshopper Sparrow in Wyoming is projected to stay roughly flat through 2029, near 2.6 (95% range 0.52–4.6). A 5-year backtest shows a typical error of ±71.9%, 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 →
20252.50.404.5
20262.50.434.5
20272.50.464.6
20282.60.494.6
20292.60.524.6

Grasshopper Sparrow Survey Routes in Wyoming

Routes recording Grasshopper 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 →
Chugwater3620242011
Recluse1820241981
Upton1720241987
Arvada1520241995
Sussex1420241992
Raven1420241992
Newcastle1320241989
Shawnee1320241988
Gvnt Valley1320241992
Riverview1120221984
Soda Well1020241979
Worland920241992
Kaycee920242024
Nowood819901990
Bill820181992
Dayton820241984
Harland Flat820171991
Highlight820071989
Elk Horn720181992
Wyarno620181975
Pine Bluff620241993
Welch620181996
Rozet620231991
Savageton620192019
Thunder Basin620152014

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsin

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