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

House Sparrow Population Trend in Pennsylvania

All statesGeneralists

House Sparrow in Pennsylvania has fallen sharply: down 72% on the route-weighted index since 1968.

-72%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 →
132Routes 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 House Sparrow 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 declinecomputed 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 →

House Sparrow has fallen sharply in Pennsylvania: down 72% on the route-weighted index since 1968.

House Sparrow Population Forecast in Pennsylvania

If the recent trend holds, House Sparrow in Pennsylvania is projected to fall about 50% by 2029 — from 21 in 2024 to a central estimate of 10 (95% range 0.00–23). A 5-year backtest shows a typical error of ±32.4%, with 100% of held-out values landing inside the 95% band.

-50%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 →
0.00–2395% 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 →
±32.4%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, House Sparrow in Pennsylvania is projected to fall about 50% by 2029 — from 21 in 2024 to a central estimate of 10 (95% range 0.00–23). A 5-year backtest shows a typical error of ±32.4%, 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 →
2025130.6426
2026130.0025
2027120.0025
2028110.0024
2029100.0023

House Sparrow Survey Routes in Pennsylvania

Routes recording House Sparrow 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 →
Ryde27120051968
Leola23920241998
Akron20519971989
Sporting Hil17619771977
Mount Joy17320241978
Big Flat14919811966
Ephrata12819881969
Mt Gretna12320001966
Labott11119831966
Portersville10519881973
Drehersville 210520242000
Drehersville10219991966
Brunnerville 210120242010
Aspers9819891968
Doubling Gap9619771966
Sardis8819741967
Scheafferstn7120011966
Gatchelville6919901972
Schaefferstown 26920242002
Akeley6719791966
Harmonsburg6320231966
Martinsburg6220241970
Brunnerville6120091969
Collegeville5920241971
Geeseytown5320241987

House Sparrow 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.