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

Purple Finch Population Trend in Washington

All statesGeneralists

Purple Finch in Washington has declined: down 31% on the route-weighted index since 1970.

-31%Since 1970TrendPercent 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 →
56YearsYears 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 WashingtonNotable 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 Washington. See the full index history below.

Purple Finch Population Forecast in Washington

If the recent trend holds, Purple Finch in Washington is projected to fall about 56% by 2029 — from 3.3 in 2024 to a central estimate of 1.5 (95% range 0.00–3.6). A 5-year backtest shows a typical error of ±45.4%, with 100% of held-out values landing inside the 95% band.

-56%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 →
1.5Projected 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 →
0.00–3.695% 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 →
±45.4%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 Washington is projected to fall about 56% by 2029 — from 3.3 in 2024 to a central estimate of 1.5 (95% range 0.00–3.6). A 5-year backtest shows a typical error of ±45.4%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20251.60.003.7
20261.60.003.7
20271.50.003.7
20281.50.003.6
20291.50.003.6

Purple Finch Survey Routes in Washington

Routes recording Purple Finch in Washington.
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 →
Leavenworth1720241981
Ilwaco1720241975
Warm Beach1620171969
Rainier1620191993
Vashon Is.1420241995
South Elma1420241984
Port Angeles1320241970
Kendall1320241981
Taholah1220221969
Ardenvoir1119721968
Mcchord1120151996
L. Wenatchee1120241994
Mazama1020221993
Issaquah919871969
Blewett Pass820241995
Carnation820241988
Mendota 3820242005
Twisp720241985
Winthrop720101990
Everett720241977
Warm Beach 2720242018
Bunker Hill620241968
Rimrock620241973
Mendota619881979
Bay View620171996

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiooregonpennsylvaniarhode-islandvermontwest-virginiawisconsin

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