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

Field Sparrow Population Trend in Pennsylvania

All statesForest birds

Field Sparrow in Pennsylvania has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 Field 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 →

Field Sparrow has fallen sharply in Pennsylvania: down 61% on the route-weighted index since 1968.

Field Sparrow Population Forecast in Pennsylvania

If the recent trend holds, Field Sparrow in Pennsylvania is projected to fall about 40% by 2030 — from 4.6 in 2025 to a central estimate of 2.8 (95% range 0.73–4.8). A 5-year backtest shows a typical error of ±29.3%, with 100% of held-out values landing inside the 95% band.

-40%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 →
2.8Projected 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 →
0.73–4.895% 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 →
±29.3%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, Field Sparrow in Pennsylvania is projected to fall about 40% by 2030 — from 4.6 in 2025 to a central estimate of 2.8 (95% range 0.73–4.8). A 5-year backtest shows a typical error of ±29.3%, 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 →
20263.31.35.4
20273.21.25.2
20283.01.05.1
20292.90.884.9
20302.80.734.8

Field Sparrow Survey Routes in Pennsylvania

Routes recording Field 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 →
Needmore2619911966
Doubling Gap2219771966
Aspers2119891968
Pine Gr Mill2020251967
Duvall1920211974
Stoneybreak1920251992
Rector1719771966
Sardis1619741967
Labott1619831966
Berwick1620251985
Sigel1520251981
Ryde1320051968
Jefferson1320251966
Rush1220251970
N Washington1120251967
Betula1120221973
Waller1120251971
Margaret1120251969
Drehersville1119991966
Austinville1020251966
Wakena1020231969
Geeseytown1020251987
Mifflintown1020251966
Jeannette1020231979
Garrett920251966

Field Sparrow Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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