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Species · Pennsylvania · BBS 2025 Release · 1966–2024

Northern House Wren Population Trend in Pennsylvania

All statesForest birds

Northern House Wren in Pennsylvania has held roughly steady: up 4% on the route-weighted index since 1968.

+4%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 →
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 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 stay roughly flat through 2029, near 10 (95% range 6.4–14). A 5-year backtest shows a typical error of ±7.7%, with 100% of held-out values landing inside the 95% band.

+6%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 →
10Projected 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 →
6.4–1495% 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 →
±7.7%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 stay roughly flat through 2029, near 10 (95% range 6.4–14). A 5-year backtest shows a typical error of ±7.7%, 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 →
2025116.614
2026106.614
2027106.514
2028106.514
2029106.414

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 →
Harmonsburg3620231966
Sigel3120241981
Collegeville3120241971
Sardis2619741969
Middletown2420241973
West Grove2419961966
Ramsey2320231968
Pottstown2319871966
Canadensis2220241969
Portersville2219881973
Doe Run2220241969
Millville2120241969
Ryde2120051968
Scheafferstn2120011966
Virginia2020241969
Betula1920221973
Brunnerville1920091969
Mt Gretna 21920222001
Schaefferstown 21920242002
Waller1820241971
Honesdale1820241972
Greentown1820241969
Poyntelle1820241969
Rector1819771966
Drehersville 21820242000

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 2026-05-22.