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Species · Pennsylvania · BBS 2025 Release · 1966–2024

Henslow's Sparrow Population Trend in Pennsylvania

All statesGrassland birds

Henslow's Sparrow in Pennsylvania has collapsed: down 94% on the route-weighted index since 1968.

-94%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 →
36Routes 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Henslow's 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 →

Henslow's Sparrow has collapsed in Pennsylvania: down 94% on the route-weighted index since 1968.

Henslow's Sparrow Population Forecast in Pennsylvania

If the recent trend holds, Henslow's Sparrow in Pennsylvania is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±109.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2020TrendPercent 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 →
0.00Projected 2020 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0995% 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 →
±109.9%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, Henslow's Sparrow in Pennsylvania is projected to stay roughly flat through 2020, near 0.00 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±109.9%, with 100% of held-out values landing inside the 95% band.19662020
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 →
20160.000.000.09
20170.000.000.09
20180.000.000.09
20190.000.000.09
20200.000.000.09

Henslow's Sparrow Survey Routes in Pennsylvania

Routes recording Henslow's 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 →
Rasselas520041981
Clover419931993
Wakena420001979
Sigel319991981
Harmonsburg219841967
Akeley219721966
Shelocta219951985
Munson220011997
Sugar Grove219841983
Slippery Rk119751975
Espyville119971967
Ferris Crnrs119681968
Wyalusing119901990
Teepleville119711966
N Washington120151968
N Pine Grove119861969
Pottersdale120022001
Odin120091982
Mars120101992
Eldred120052005
Laurel Hill119791979
Austinville119941994
Hop Bottom119931967
Honesdale120021996
Portersville119751975

Henslow's Sparrow Population Trend in Other States

delawareillinoisindianaiowakansaskentuckymarylandmichiganminnesotamissourinebraskanew-yorknorth-carolinanorth-dakotaohiooklahomasouth-dakotavermontvirginiawest-virginiawisconsin

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