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

Purple Finch Population Trend in Wisconsin

All statesForest birds

Purple Finch in Wisconsin has declined: down 28% on the route-weighted index since 1968.

-28%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 →
58Routes 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 Purple Finch 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 Purple Finch in Wisconsin. See the full index history below.

Purple Finch Population Forecast in Wisconsin

If the recent trend holds, Purple Finch in Wisconsin is projected to stay roughly flat through 2030, near 0.81 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.

+1%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 →
0.81Projected 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 →
0.33–1.395% 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 →
±18.7%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, Purple Finch in Wisconsin is projected to stay roughly flat through 2030, near 0.81 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±18.7%, with 100% 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 →
20260.830.341.3
20270.820.341.3
20280.820.341.3
20290.810.331.3
20300.810.331.3

Purple Finch Survey Routes in Wisconsin

Routes recording Purple Finch 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 →
Washington I920251967
Land O Lakes720161967
Wausaukee720251980
Bayfield620251967
Dresser420121993
Phillips420251966
Rhinelander420221998
Minong320241967
Union Twp320251968
Rib Lake320241966
Eagle River320251966
Crandon320251967
Mellen320251998
Flambeau320251998
Land O' Lakes 2320252017
Chaffey220251970
Merrill220241966
Irma220251967
Mcnaughton220241966
Popple River220251966
Amberg220251980
Stratford220121970
Oconto Falls220221974
Amnicon Falls220251998
Weirgor Springs220191999

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiooregonpennsylvaniarhode-islandvermontwashingtonwest-virginia

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