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Species · Pennsylvania · BBS 2026 Release · 1966–2025

Swamp Sparrow Population Trend in Pennsylvania

All statesWetland birds

Swamp Sparrow in Pennsylvania has risen sharply: up 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 →
71Routes 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 Swamp 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 increasecomputed 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 →

Swamp Sparrow has risen sharply in Pennsylvania: up 61% on the route-weighted index since 1968.

Swamp Sparrow Population Forecast in Pennsylvania

If the recent trend holds, Swamp Sparrow in Pennsylvania is projected to fall about 29% by 2030 — from 1.0 in 2025 to a central estimate of 0.72 (95% range 0.48–0.96). A 5-year backtest shows a typical error of ±27.7%, with 40% of held-out values landing inside the 95% band.

-29%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 →
0.72Projected 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 →
0.48–0.9695% 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 →
±27.7%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, Swamp Sparrow in Pennsylvania is projected to fall about 29% by 2030 — from 1.0 in 2025 to a central estimate of 0.72 (95% range 0.48–0.96). A 5-year backtest shows a typical error of ±27.7%, with 40% 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 →
20260.690.450.93
20270.690.460.94
20280.700.460.94
20290.710.470.95
20300.720.480.96

Swamp Sparrow Survey Routes in Pennsylvania

Routes recording Swamp 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 →
Betula1420221987
Honesdale1320251972
Ferris Crnrs1020251966
Logue1020251970
Eldred820221995
N Washington620251984
Starlight619921970
Teepleville520251966
Greentown520241973
Poyntelle520251969
Ridgway419921989
Rasselas420221989
Austinville420251967
Sugar Grove420251983
Roulette 2420252022
Harmonsburg320251968
Arnot320251971
Little Marsh320241972
Rush320251973
Hometown319661966
Clearfield320021968
Harrisville320251997
Akeley219751966
Ellenton220251982
Canadensis220182015

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisindianaiowamainemarylandmassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiorhode-islandsouth-dakotavermontvirginiawest-virginiawisconsin

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