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

Sora Population Trend in Wisconsin

All statesWetland birds

Sora in Wisconsin has collapsed: down 85% on the route-weighted index since 1968.

-85%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 →
64Routes 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 Sora 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 →

Sora has collapsed in Wisconsin: down 85% on the route-weighted index since 1968.

Sora Population Forecast in Wisconsin

If the recent trend holds, Sora in Wisconsin is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.19). A 5-year backtest shows a typical error of ±40.3%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.02Projected 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 →
0.00–0.1995% 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 →
±40.3%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, Sora in Wisconsin is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.19). A 5-year backtest shows a typical error of ±40.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.030.000.20
20260.030.000.20
20270.030.000.20
20280.020.000.19
20290.020.000.19

Sora Survey Routes in Wisconsin

Routes recording Sora 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 →
Dresser320171968
Merrill319731973
Hudson219961967
Exeland220171968
Holway219781976
Stevens Pt220192019
Oconto Falls220041971
Omro219961968
Brownsville219751974
Buena Vista220142005
Chaffey119901968
Iron River120181972
Minong120141974
Grand View119921992
Shanagolden119751975
Montreal119841984
Union Twp120191966
Loraine120161966
Cumberland119981967
Weyerhauser120241967
Couderay119761976
Gilman120231967
Phillips120141978
Rib Lake119911978
Irma119901973

Sora Population Trend in Other States

alaskaarizonacaliforniacoloradoidahoillinoisindianaiowakansasmainemassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-dakotaohiooregonpennsylvaniasouth-dakotautahvermontwashingtonwyoming

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