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

Pine Warbler Population Trend in Illinois

All statesForest birds

Pine Warbler in Illinois has held roughly steady: down 9% on the route-weighted index since 1975.

-9%Since 1975TrendPercent 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 →
8Routes 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 Pine Warbler Trends in IllinoisNotable 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 Pine Warbler in Illinois. See the full index history below.

Pine Warbler Population Forecast in Illinois

If the recent trend holds, Pine Warbler in Illinois is projected to fall about 19% by 2030 — from 0.07 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±47.2%, with 100% of held-out values landing inside the 95% band.

-19%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 →
0.05Projected 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 →
0.00–0.1395% 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 →
±47.2%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, Pine Warbler in Illinois is projected to fall about 19% by 2030 — from 0.07 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±47.2%, with 100% of held-out values landing inside the 95% band.19732030
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 →
20260.050.000.13
20270.050.000.13
20280.050.000.13
20290.050.000.13
20300.050.000.13

Pine Warbler Survey Routes in Illinois

Routes recording Pine Warbler in Illinois.
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 →
Delwood520251973
Cave In Rock320241993
Bremen220152013
Karnak120022002
Union120172017
Sandusky119971994
Brnt Prairie119971997
Beaverdam Lk120221975

Pine Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaindianakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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