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Species · Wisconsin · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher Population Trend in Wisconsin

All statesForest birds

Blue-gray Gnatcatcher in Wisconsin has surged: up 15× on the route-weighted index since 1974.

15×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 →
51YearsYears 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 →

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 →

Blue-gray Gnatcatcher has surged in Wisconsin: up 15× on the route-weighted index since 1974.

Blue-gray Gnatcatcher Population Forecast in Wisconsin

If the recent trend holds, Blue-gray Gnatcatcher in Wisconsin is projected to rise about 58% by 2029 — from 0.51 in 2024 to a central estimate of 0.80 (95% range 0.52–1.1). A 5-year backtest shows a typical error of ±68.1%, with 0% of held-out values landing inside the 95% band.

+58%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 →
0.80Projected 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 →
0.52–1.195% 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 →
±68.1%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 58% by 2029 — from 0.51 in 2024 to a central estimate of 0.80 (95% range 0.52–1.1). A 5-year backtest shows a typical error of ±68.1%, with 0% 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 →
20250.750.471.0
20260.760.481.0
20270.770.491.1
20280.790.511.1
20290.800.521.1

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 →
Highland420241998
N Freedom420241980
Hebron420241989
Mukwonago 2420242005
Hudson320161991
Gilmanton320241984
Trempealeau320101979
Cadott320241966
Gresham320242001
Clintonville320131991
Newburg Crns320221994
Pardeeville320241985
Fall River320231987
Beloit320172001
Loraine220011992
Verona220171995
Wis Rapids220112006
Manawa220241983
Oconto Falls220181974
Kendall220231970
Princeton220191992
Rolling Pr220142005
Grimms220172012
Paris220241993
Raymond220232009

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 2026-05-22.