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Species · Washington · BBS 2025 Release · 1966–2024

Grasshopper Sparrow Population Trend in Washington

All statesGrassland birds

Grasshopper Sparrow in Washington has surged: up 102% on the route-weighted index since 1973.

+102%Since 1973TrendPercent 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 →
44Routes 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 →
50YearsYears 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 WashingtonNotable 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 surged in Washington: up 102% on the route-weighted index since 1973.

Grasshopper Sparrow Population Forecast in Washington

If the recent trend holds, Grasshopper Sparrow in Washington is projected to rise about 637% by 2029 — from 0.19 in 2024 to a central estimate of 1.4 (95% range 0.35–2.5). A 5-year backtest shows a typical error of ±429.9%, with 20% of held-out values landing inside the 95% band.

+637%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 →
1.4Projected 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 →
0.35–2.595% 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 →
±429.9%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 Washington is projected to rise about 637% by 2029 — from 0.19 in 2024 to a central estimate of 1.4 (95% range 0.35–2.5). A 5-year backtest shows a typical error of ±429.9%, with 20% 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 →
20251.40.292.4
20261.40.312.4
20271.40.322.5
20281.40.342.5
20291.40.352.5

Grasshopper Sparrow Survey Routes in Washington

Routes recording Grasshopper Sparrow in Washington.
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 →
Arid Land Er2919961988
Hatton2919941992
Ewan1620191983
Bickleton1220191996
Richland720242006
Hanford Site619961988
Harrington620051988
Wilbur520191983
Kamilche419711971
Laurier420221998
Snowden319861986
Sulphur320221995
Deer Park320152015
Mercer220181982
Winthrop219921992
Ilwaco219971997
Waitsburg220032003
Brewster120181977
Chewelah120061993
Ewan 2120232023
Turnbull Nwr120231994
L Pend O Nwr120082008
Moses Lake120141973
Reardan120221968
Columbia Nwr120151992

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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