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

Alder Flycatcher Population Trend in Wisconsin

All statesAerial insectivores

Alder Flycatcher in Wisconsin has surged: up 77% on the route-weighted index since 1968.

+77%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 →
58YearsYears 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 surged in Wisconsin: up 77% 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 104% by 2029 — from 1.4 in 2024 to a central estimate of 2.8 (95% range 1.9–3.8). A 5-year backtest shows a typical error of ±59.1%, with 40% of held-out values landing inside the 95% band.

+104%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 →
2.8Projected 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 →
1.9–3.895% 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 →
±59.1%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 104% by 2029 — from 1.4 in 2024 to a central estimate of 2.8 (95% range 1.9–3.8). A 5-year backtest shows a typical error of ±59.1%, with 40% 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 →
20252.71.83.7
20262.81.83.7
20272.81.83.7
20282.81.93.8
20292.81.93.8

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 →
Gilman1420241966
Weirgor Springs1420241999
Amnicon Falls1020241998
Iron River920241967
Rhinelander920231998
Flambeau820241998
Couderay720191969
Merrill620241966
Chaffey520231966
Bayfield520241974
Gilmanton520102004
Grand View420241992
Montreal420241968
Loraine420211973
Land O' Lakes 2420242017
Mellen420241998
Cavour420241998
Grimms420211998
Irma320231967
Popple River320241966
Omro320011978
Buena Vista320222001
Shanagolden220231969
Land O Lakes220161970
Dresser220231992

Alder Flycatcher Population Trend in Other States

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

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