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

Bobolink Population Trend in Pennsylvania

All statesGrassland birds

Bobolink in Pennsylvania has declined: down 34% on the route-weighted index since 1968.

-34%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 →
100Routes 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 Bobolink 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 →

No notable trend signals for Bobolink in Pennsylvania. See the full index history below.

Bobolink Population Forecast in Pennsylvania

If the recent trend holds, Bobolink in Pennsylvania is projected to rise about 21% by 2030 — from 2.8 in 2025 to a central estimate of 3.4 (95% range 1.4–5.3). A 5-year backtest shows a typical error of ±35.8%, with 100% of held-out values landing inside the 95% band.

+21%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 →
3.4Projected 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 →
1.4–5.395% 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 →
±35.8%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, Bobolink in Pennsylvania is projected to rise about 21% by 2030 — from 2.8 in 2025 to a central estimate of 3.4 (95% range 1.4–5.3). A 5-year backtest shows a typical error of ±35.8%, 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 →
20263.41.55.4
20273.41.55.4
20283.41.55.3
20293.41.45.3
20303.41.45.3

Bobolink Survey Routes in Pennsylvania

Routes recording Bobolink 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 →
Arnot6020251969
Little Marsh4720241967
Honesdale2620251972
Rush2420251970
Greentown1820231969
Susquehanna1820251971
Starlight 21720252000
Ellenton1620251982
Poyntelle1420251969
Starlight1219991970
Austinville1020251966
Akeley919791966
West Grove819921970
Sigel720251981
Eldred720141973
Waller720251971
Brunnerville720041982
Roulette 2720252022
Garrett620251966
Brick Tavern619911991
Wyalusing620251985
Odin520241973
Mawr Glen520251966
Bow Bridge520251969
Logue420231970

Bobolink Population Trend in Other States

californiacoloradoconnecticutidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonrhode-islandsouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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