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Species · Wisconsin · BBS 2026 Release · 1966–2025

Grasshopper Sparrow Population Trend in Wisconsin

All statesGrassland birds

Grasshopper Sparrow in Wisconsin has collapsed: down 94% on the route-weighted index since 1968.

-94%Since 1968TrendPercent 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 →
78Routes 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 →
59YearsYears 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 WisconsinNotable 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 declinecomputed 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 collapsed in Wisconsin: down 94% on the route-weighted index since 1968.

Grasshopper Sparrow Population Forecast in Wisconsin

If the recent trend holds, Grasshopper Sparrow in Wisconsin is projected to fall about 100% by 2030 — from 0.23 in 2025 to a central estimate of 0.00 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±198.9%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.095% 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 →
±198.9%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 Wisconsin is projected to fall about 100% by 2030 — from 0.23 in 2025 to a central estimate of 0.00 (95% range 0.00–1.0). A 5-year backtest shows a typical error of ±198.9%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.000.001.0
20270.000.001.0
20280.000.001.0
20290.000.001.0
20300.000.001.0

Grasshopper Sparrow Survey Routes in Wisconsin

Routes recording Grasshopper Sparrow in Wisconsin.
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 →
Cochrane1019871966
Rolling Pr619771966
Cumberland520031969
N Freedom520251966
Loraine420061966
Phillips320071966
Oconto Falls320091968
Rhinelander320092008
Prairie Du Chien320252005
Briggsville320251999
Iron River220231970
Weyerhauser220231966
Couderay219971969
Irma219701970
Washington I220251968
Clintonville220191967
Casco220081966
Eden219911976
Hazel Green220071966
Wiota220251966
Paris220011966
Stetsonville220182013
Chaffey119921992
Minong119831982
Shanagolden119741974

Grasshopper Sparrow Population Trend in Other States

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

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