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

Hairy Woodpecker Population Trend in Pennsylvania

All statesForest birds

Hairy Woodpecker in Pennsylvania has surged: up 79% on the route-weighted index since 1968.

+79%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 →
134Routes 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 Hairy Woodpecker Trends in PennsylvaniaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Hairy Woodpecker has surged in Pennsylvania: up 79% on the route-weighted index since 1968.

Hairy Woodpecker Population Forecast in Pennsylvania

If the recent trend holds, Hairy Woodpecker in Pennsylvania is projected to rise about 11% by 2029 — from 0.78 in 2024 to a central estimate of 0.86 (95% range 0.63–1.1). A 5-year backtest shows a typical error of ±9.4%, with 100% of held-out values landing inside the 95% band.

+11%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 →
0.86Projected 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 →
0.63–1.195% 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 →
±9.4%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, Hairy Woodpecker in Pennsylvania is projected to rise about 11% by 2029 — from 0.78 in 2024 to a central estimate of 0.86 (95% range 0.63–1.1). A 5-year backtest shows a typical error of ±9.4%, 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 →
20250.830.601.1
20260.840.611.1
20270.840.621.1
20280.850.631.1
20290.860.631.1

Hairy Woodpecker Survey Routes in Pennsylvania

Routes recording Hairy Woodpecker in Pennsylvania.
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 →
Poyntelle720181969
N Pine Grove620241982
Eldred520221973
Bald Eagle520211971
Ryde520051968
Arnot420241998
Warrens Mill420241971
Landisburg420231978
Espyville320241971
Harmonsburg320221976
Russell City320241969
Rasselas320221970
Rush320171970
Ralston319731966
Hop Bottom320181968
Martinsburg320231990
Munson320241979
Peru Mills320231966
Naginey320211970
Collegeville320231981
Sproul Sf-A320242003
Slippery Rk219781978
Clover220171989
Ferris Crnrs220241986
Teepleville220241966

Hairy Woodpecker Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonrhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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