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

Clay-colored Sparrow Population Trend in Wisconsin

All statesGrassland birds

Clay-colored Sparrow in Wisconsin has declined: down 47% on the route-weighted index since 1968.

-47%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 →
88Routes 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 Clay-colored 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 →

No notable trend signals for Clay-colored Sparrow in Wisconsin. See the full index history below.

Clay-colored Sparrow Population Forecast in Wisconsin

If the recent trend holds, Clay-colored Sparrow in Wisconsin is projected to rise about 93% by 2030 — from 1.2 in 2025 to a central estimate of 2.3 (95% range 1.2–3.4). A 5-year backtest shows a typical error of ±120.8%, with 0% of held-out values landing inside the 95% band.

+93%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 →
2.3Projected 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 →
1.2–3.495% 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 →
±120.8%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, Clay-colored Sparrow in Wisconsin is projected to rise about 93% by 2030 — from 1.2 in 2025 to a central estimate of 2.3 (95% range 1.2–3.4). A 5-year backtest shows a typical error of ±120.8%, with 0% 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 →
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Clay-colored Sparrow Survey Routes in Wisconsin

Routes recording Clay-colored 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 →
Hudson1420251966
Amnicon Falls1320251998
Iron River1020251967
Bayfield720251967
Weyerhauser720241966
Gilman620251966
Minong520251967
Holway519891967
Grimms520212004
Merrill420251966
Loraine320251966
Wausaukee320231980
Saxeville320241969
Manitowoc320211968
Casco320251994
Eden320212014
Omro 2320252006
Bashaw320251998
Meridean320251998
Buena Vista320231998
Grand View220251966
Land O Lakes220161976
Union Twp220251967
Mcnaughton220101967
Stevens Pt220181966

Clay-colored Sparrow Population Trend in Other States

coloradoillinoisindianaiowamainemichiganminnesotamontananebraskanew-yorknorth-dakotapennsylvaniasouth-dakotautahwashingtonwyoming

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