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Species · Wisconsin · BBS 2026 Release · 1966–2025

Alder Flycatcher Population Trend in Wisconsin

All statesAerial insectivores

Alder Flycatcher in Wisconsin has risen sharply: up 67% on the route-weighted index since 1968.

+67%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 →
91Routes 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 Alder Flycatcher 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 →

Alder Flycatcher has risen sharply in Wisconsin: up 67% on the route-weighted index since 1968.

Alder Flycatcher Population Forecast in Wisconsin

If the recent trend holds, Alder Flycatcher in Wisconsin is projected to rise about 79% by 2030 — from 1.6 in 2025 to a central estimate of 2.8 (95% range 1.8–3.8). A 5-year backtest shows a typical error of ±74.1%, with 20% of held-out values landing inside the 95% band.

+79%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 →
2.8Projected 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 →
1.8–3.895% 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 →
±74.1%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, Alder Flycatcher in Wisconsin is projected to rise about 79% by 2030 — from 1.6 in 2025 to a central estimate of 2.8 (95% range 1.8–3.8). A 5-year backtest shows a typical error of ±74.1%, with 20% 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 →
20262.71.73.6
20272.71.73.7
20282.71.83.7
20292.81.83.7
20302.81.83.8

Alder Flycatcher Survey Routes in Wisconsin

Routes recording Alder Flycatcher 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 →
Amnicon Falls2320251998
Rhinelander920231998
Weirgor Springs820251999
Iron River720251967
Amberg720251980
Bashaw720251998
Montreal620251968
Rib Lake620251966
Flambeau620251998
Gilmanton520102004
Bayfield420251974
Popple River420251966
Grimms420211998
Chaffey320251966
Shanagolden320251969
Cumberland320251966
Gilman320251966
Merrill320251966
Omro320011978
Land O' Lakes 2320252017
Cavour320251998
Buena Vista320222001
Land O Lakes220161970
Dresser220231992
Weyerhauser220241968

Alder Flycatcher Population Trend in Other States

alaskaconnecticutidahoillinoisindianaiowamainemarylandmassachusettsmichiganminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-dakotavermontvirginiawashingtonwest-virginia

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