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Species · Wisconsin · BBS 2026 Release · 1966–2025

Blue-gray Gnatcatcher Population Trend in Wisconsin

All statesForest birds

Blue-gray Gnatcatcher in Wisconsin has surged: up 16× on the route-weighted index since 1974.

16×Since 1974TrendPercent 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 →
65Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blue-gray Gnatcatcher 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 Blue-gray Gnatcatcher in Wisconsin. See the full index history below.

Blue-gray Gnatcatcher Population Forecast in Wisconsin

If the recent trend holds, Blue-gray Gnatcatcher in Wisconsin is projected to rise about 68% by 2030 — from 0.47 in 2025 to a central estimate of 0.79 (95% range 0.50–1.1). A 5-year backtest shows a typical error of ±69.6%, with 0% of held-out values landing inside the 95% band.

+68%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 →
0.79Projected 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 →
0.50–1.195% 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 →
±69.6%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, Blue-gray Gnatcatcher in Wisconsin is projected to rise about 68% by 2030 — from 0.47 in 2025 to a central estimate of 0.79 (95% range 0.50–1.1). A 5-year backtest shows a typical error of ±69.6%, 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 →
20260.740.451.0
20270.750.471.0
20280.760.481.1
20290.780.491.1
20300.790.501.1

Blue-gray Gnatcatcher Survey Routes in Wisconsin

Routes recording Blue-gray Gnatcatcher 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 →
Pardeeville520251985
Paris520251993
Highland420241998
New Lisbon420251981
N Freedom420251980
Hebron420241989
Hudson320161991
Trempealeau320101979
Cadott320241966
Clintonville320131991
Newburg Crns320221994
Beloit320172001
Loraine220011992
Amberg220251989
Wis Rapids220112006
Manawa220241983
Oconto Falls220181974
Gresham220252001
Princeton220191992
Fall River220251987
Rolling Pr220142005
Wiota220251986
Grimms220172012
Raymond220232009
Holland220022001

Blue-gray Gnatcatcher Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawyoming

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