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

Purple Finch Population Trend in Michigan

All statesGeneralists

Purple Finch in Michigan has declined: down 29% on the route-weighted index since 1968.

-29%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 →
70Routes 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 MichiganNotable 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 Michigan. See the full index history below.

Purple Finch Population Forecast in Michigan

If the recent trend holds, Purple Finch in Michigan is projected to stay roughly flat through 2029, near 0.75 (95% range 0.11–1.4). A 5-year backtest shows a typical error of ±109.9%, with 100% of held-out values landing inside the 95% band.

+6%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 →
0.75Projected 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 →
0.11–1.495% 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 →
±109.9%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 Michigan is projected to stay roughly flat through 2029, near 0.75 (95% range 0.11–1.4). A 5-year backtest shows a typical error of ±109.9%, 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 →
20250.760.121.4
20260.750.121.4
20270.750.111.4
20280.750.111.4
20290.750.111.4

Purple Finch Survey Routes in Michigan

Routes recording Purple Finch in Michigan.
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 →
Muskallonge620241966
Riggsville620191967
Herman520151983
Walloon Lake520041977
Walloon Lake 2420102005
Sidnaw420241998
Pleasant Valley 2420242024
Wilson320101966
Shingleton320241977
Red Oak320121979
Hubbard Lake319961975
Tyre319781978
Ensign320092006
Gooseneck320092008
Bootjack220231967
Ned Lake220241986
Maple Grove220241967
Ishpeming220231980
Frederic 2220092005
Tahquamenon220241974
Gilchrist220211976
Irons219891970
Skegemog Pt220131980
Frederic220011971
Sand Lake220211979

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiooregonpennsylvaniarhode-islandvermontwashingtonwest-virginiawisconsin

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