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

Purple Finch Population Trend in Wisconsin

All statesGeneralists

Purple Finch in Wisconsin has declined: down 26% on the route-weighted index since 1968.

-26%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 →
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 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 rise about 10% by 2029 — from 0.74 in 2024 to a central estimate of 0.82 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±35.5%, with 100% of held-out values landing inside the 95% band.

+10%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 →
0.82Projected 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 →
0.33–1.395% 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 →
±35.5%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 rise about 10% by 2029 — from 0.74 in 2024 to a central estimate of 0.82 (95% range 0.33–1.3). A 5-year backtest shows a typical error of ±35.5%, with 100% 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 →
20250.830.351.3
20260.830.341.3
20270.830.341.3
20280.820.341.3
20290.820.331.3

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 →
Land O Lakes720161967
Iron River520241967
Eagle River520241966
Wausaukee520241980
Washington I520241967
Dresser420121993
Irma420241967
Rhinelander420221998
Cavour420231998
Minong320241967
Grand View320241967
Bayfield320241967
Phillips320241966
Rib Lake320241966
Amnicon Falls320241998
Chaffey220241970
Merrill220241966
Mcnaughton220241966
Popple River220241966
Amberg220241980
Stratford220121970
Oconto Falls220221974
Bashaw220172006
Weirgor Springs220191999
River Falls220162016

Purple Finch Population Trend in Other States

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

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