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

Northern House Wren Population Trend in Pennsylvania

All statesForest birds

Northern House Wren in Pennsylvania has held roughly steady: down 1% on the route-weighted index since 1968.

-1%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 →
136Routes 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 →
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 Northern House Wren 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 →

No notable trend signals for Northern House Wren in Pennsylvania. See the full index history below.

Northern House Wren Population Forecast in Pennsylvania

If the recent trend holds, Northern House Wren in Pennsylvania is projected to rise about 10% by 2030 — from 9.2 in 2025 to a central estimate of 10 (95% range 6.3–14). A 5-year backtest shows a typical error of ±6.8%, with 100% of held-out values landing inside the 95% band.

+10%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 →
10Projected 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 →
6.3–1495% 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 →
±6.8%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, Northern House Wren in Pennsylvania is projected to rise about 10% by 2030 — from 9.2 in 2025 to a central estimate of 10 (95% range 6.3–14). A 5-year backtest shows a typical error of ±6.8%, 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 →
2026106.514
2027106.514
2028106.414
2029106.414
2030106.314

Northern House Wren Survey Routes in Pennsylvania

Routes recording Northern House Wren 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 →
Collegeville3120241971
Sardis2619741969
West Grove2419961966
Pottstown2319871966
Portersville2219881973
Middletown2220251973
Poyntelle2120251969
Ryde2120051968
Scheafferstn2120011966
Jacobus2120251986
Sigel2020251981
N Washington2020251967
Honesdale2020251972
Betula1920221973
Rush1920251970
Canadensis1920251969
Brunnerville1920091969
Mt Gretna 21920222001
Drehersville 21920252000
Wild Creek1920251988
Greentown1820241969
Rector1819771966
Bendersville1820241990
Espyville1720251967
Harmonsburg1720251966

Northern House Wren Population Trend in Other States

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

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