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

Purple Finch Population Trend in Maryland

All statesForest birds

Purple Finch in Maryland has surged: up 347% on the route-weighted index since 1977.

+347%Since 1977TrendPercent 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 →
9Routes 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 →
42YearsYears 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 MarylandNotable 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 Maryland. See the full index history below.

Purple Finch Population Forecast in Maryland

If the recent trend holds, Purple Finch in Maryland is projected to fall about 11% by 2030 — from 0.10 in 2025 to a central estimate of 0.09 (95% range 0.03–0.16). A 5-year backtest shows a typical error of ±115.2%, with 60% of held-out values landing inside the 95% band.

-11%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 →
0.09Projected 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 →
0.03–0.1695% 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 →
±115.2%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 Maryland is projected to fall about 11% by 2030 — from 0.10 in 2025 to a central estimate of 0.09 (95% range 0.03–0.16). A 5-year backtest shows a typical error of ±115.2%, with 60% of held-out values landing inside the 95% band.19722030
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 →
20260.090.020.16
20270.090.020.16
20280.090.020.16
20290.090.020.16
20300.090.030.16

Purple Finch Survey Routes in Maryland

Routes recording Purple Finch in Maryland.
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 →
Accident 2220252025
Floyd120161972
Mt Nebo119901983
Vindex120221979
Potomac Park119851985
Accident120161995
Jennings120251995
Steyer120242006
Finzel120251996

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiooregonpennsylvaniarhode-islandvermontwashingtonwest-virginiawisconsin

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