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

Field Sparrow Population Trend in Pennsylvania

All statesGeneralists

Field Sparrow in Pennsylvania has fallen sharply: down 62% on the route-weighted index since 1968.

-62%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 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 62% 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 41% by 2029 — from 4.8 in 2024 to a central estimate of 2.8 (95% range 0.80–4.8). A 5-year backtest shows a typical error of ±26.4%, with 100% of held-out values landing inside the 95% band.

-41%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 →
2.8Projected 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 →
0.80–4.895% 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 →
±26.4%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, Field Sparrow in Pennsylvania is projected to fall about 41% by 2029 — from 4.8 in 2024 to a central estimate of 2.8 (95% range 0.80–4.8). A 5-year backtest shows a typical error of ±26.4%, 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 →
20253.41.45.4
20263.31.25.3
20273.11.15.1
20283.00.945.0
20292.80.804.8

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
Duvall1920211974
Rector1719771966
Sardis1619741967
Labott1619831966
Drehersville 21620242000
Peru Mills1520241966
Stoneybreak1520241992
Millville1420241969
Pine Gr Mill1420241967
Berwick1420241985
Ryde1320051968
Warrens Mill1320241971
Austinville1220241966
Betula1120221973
Mifflintown1120241966
Drehersville1119991966
Jefferson1120241966
Wakena1020231969
Geeseytown1020241987
Jeannette1020231979
Shelocta920241968
Big Flat919811966

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 2026-05-22.