BirdAnalyst
Species · BCR 13 · BBS 2026 Release · 1966–2025

Purple Finch In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainForest birds

Purple Finch in Lower Great Lakes / St. Lawrence Plain has declined: down 48% on the route-weighted index since 1968.

-48%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 →
79Routes In RegionSurvey 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 SignalsNotable 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 Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Purple Finch In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Purple Finch in Lower Great Lakes / St. Lawrence Plain is projected to fall about 27% by 2030 — from 0.66 in 2025 to a central estimate of 0.48 (95% range 0.01–0.97). A 5-year backtest shows a typical error of ±45.8%, with 100% of held-out values landing inside the 95% band.

-27%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 →
0.48Projected 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 →
0.01–0.9795% 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 →
±45.8%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 Lower Great Lakes / St. Lawrence Plain is projected to fall about 27% by 2030 — from 0.66 in 2025 to a central estimate of 0.48 (95% range 0.01–0.97). A 5-year backtest shows a typical error of ±45.8%, 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 →
20260.520.041.00
20270.510.030.99
20280.500.020.98
20290.490.010.97
20300.480.010.97

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Purple Finch in Lower Great Lakes / St. Lawrence Plain.
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 →
Cicero CtrNEW-YORK52022
MiddlefieldOHIO51995
CatskillsNEW-YORK42007
RomulusNEW-YORK41997
RushvilleNEW-YORK42018
ParishvilleNEW-YORK42025
NaplesNEW-YORK42025
NashvilleNEW-YORK32018
OneidaNEW-YORK32009
ClintonNEW-YORK32002
HopkintonNEW-YORK32021
WaylandOHIO31999
GarrettsvileOHIO31991
Ferris CrnrsPENNSYLVANIA32025
Sugar GrovePENNSYLVANIA32024
HinesburgVERMONT31988
BristolVERMONT32025
W ShokanNEW-YORK22009
GhentNEW-YORK22004
BranchportNEW-YORK22024
Canadice LNEW-YORK22025
MendonNEW-YORK21988
HamburgNEW-YORK22025
CastileNEW-YORK22014
ByronNEW-YORK22019

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