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

Swamp Sparrow Population Trend in Pennsylvania

All statesGeneralists

Swamp Sparrow in Pennsylvania has risen sharply: up 57% on the route-weighted index since 1968.

+57%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 →
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 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 57% 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 15% by 2029 — from 0.80 in 2024 to a central estimate of 0.68 (95% range 0.46–0.90). A 5-year backtest shows a typical error of ±23.4%, with 60% of held-out values landing inside the 95% band.

-15%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 →
0.68Projected 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 →
0.46–0.9095% 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 →
±23.4%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, Swamp Sparrow in Pennsylvania is projected to fall about 15% by 2029 — from 0.80 in 2024 to a central estimate of 0.68 (95% range 0.46–0.90). A 5-year backtest shows a typical error of ±23.4%, with 60% 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 →
20250.660.430.88
20260.660.440.89
20270.670.440.89
20280.670.450.90
20290.680.460.90

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
Ferris Crnrs1320241966
Eldred820221995
Starlight 2620242015
Honesdale620241972
Starlight619921970
Greentown520241973
Poyntelle520241969
Ridgway419921989
Rasselas420221989
Sugar Grove420241983
Harmonsburg320231968
Teepleville320241966
Ellenton320241982
Arnot320241971
Little Marsh320241972
Mawr Glen320231988
Austinville320241967
Susquehanna320241975
Hometown319661966
Clearfield320021968
Akeley219751966
N Washington220241984
Logue220231970
Rush220241973

Swamp Sparrow Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.