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

Forest Birds In Pennsylvania

All statesPennsylvania

55 species in this guild. As a group they are +53%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild 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 forest birds in Pennsylvania. See the full index history below.

Forest Birds In Pennsylvania Population Forecast

If the recent trend holds, Forest birds in Pennsylvania is projected to stay roughly flat through 2029, near 5.2 (95% range 4.7–5.7). A 5-year backtest shows a typical error of ±9.8%, with 80% of held-out values landing inside the 95% band.

+10%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 →
5.2Projected 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 →
4.7–5.795% 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 →
±9.8%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, Forest birds in Pennsylvania is projected to stay roughly flat through 2029, near 5.2 (95% range 4.7–5.7). A 5-year backtest shows a typical error of ±9.8%, with 80% 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 →
20255.14.65.6
20265.14.65.6
20275.24.75.7
20285.24.75.7
20295.24.75.7

Member Species In Pennsylvania

Forest birds species in Pennsylvania.
TrendPercent 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 →
Golden-winged WarblerParulidae-96%
Kentucky WarblerParulidae-90%
Marsh WrenTroglodytidae-73%
Nashville WarblerParulidae-68%
Northern WaterthrushParulidae-61%
Swainson's ThrushTurdidae-29%
Wood ThrushTurdidae-25%
Prothonotary WarblerParulidae-25%
Golden-crowned KingletRegulidae-17%
Prairie WarblerParulidae-14%
Mourning WarblerParulidae-14%
Blue-winged WarblerParulidae-9%
American RobinTurdidae-7%
Cerulean WarblerParulidae-1%
Northern House WrenTroglodytidae+4%
Yellow WarblerParulidae+26%
Common YellowthroatParulidae+44%
Canada WarblerParulidae+46%
Red-headed WoodpeckerPicidae+51%
Yellow-throated WarblerParulidae+64%
White-eyed VireoVireonidae+65%
Downy WoodpeckerPicidae+76%
Hairy WoodpeckerPicidae+79%
VeeryTurdidae+93%
Chestnut-sided WarblerParulidae+107%
Tufted TitmouseParidae+137%
Worm-eating WarblerParulidae+142%
American RedstartParulidae+143%
Black-capped ChickadeeParidae+158%
Northern ParulaParulidae+170%
Hermit ThrushTurdidae+170%
Warbling VireoVireonidae+181%
Blue-gray GnatcatcherPolioptilidae+204%
Red-eyed VireoVireonidae+212%
Black-and-white WarblerParulidae+246%
Eastern BluebirdTurdidae+263%
Red-breasted NuthatchSittidae+269%
White-breasted NuthatchSittidae+277%
Yellow-throated VireoVireonidae+290%
Louisiana WaterthrushParulidae+364%
Pileated WoodpeckerPicidae+440%
OvenbirdParulidae+520%
Magnolia WarblerParulidae+628%
Brown CreeperCerthiidae+682%
Hooded WarblerParulidae+720%
Carolina ChickadeeParidae+763%
Blackburnian WarblerParulidae+774%
Pine WarblerParulidae+904%
Winter WrenTroglodytidae13×
Black-throated Blue WarblerParulidae18×
Black-throated Green WarblerParulidae24×
Carolina WrenTroglodytidae32×
Yellow-bellied SapsuckerPicidae44×
Red-bellied WoodpeckerPicidae45×
Blue-headed VireoVireonidae63×

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