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

Baltimore Oriole Population Trend in Illinois

All statesForest birds

Baltimore Oriole in Illinois has held roughly steady: down 6% on the route-weighted index since 1968.

-6%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 →
105Routes 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 Baltimore Oriole 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 Baltimore Oriole in Illinois. See the full index history below.

Baltimore Oriole Population Forecast in Illinois

If the recent trend holds, Baltimore Oriole in Illinois is projected to rise about 14% by 2030 — from 2.2 in 2025 to a central estimate of 2.5 (95% range 1.3–3.8). A 5-year backtest shows a typical error of ±28.2%, with 100% of held-out values landing inside the 95% band.

+14%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 →
2.5Projected 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 →
1.3–3.895% 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 →
±28.2%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, Baltimore Oriole in Illinois is projected to rise about 14% by 2030 — from 2.2 in 2025 to a central estimate of 2.5 (95% range 1.3–3.8). A 5-year backtest shows a typical error of ±28.2%, 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 →
20262.61.33.9
20272.61.33.9
20282.61.33.8
20292.61.33.8
20302.51.33.8

Baltimore Oriole Survey Routes in Illinois

Routes recording Baltimore Oriole 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 →
Terre Haute1520251966
Birds1520241977
Bradbury920251971
Lake Galena920212001
Chandlervill820251971
York820251994
New Lenox720191966
Belleview720251966
Sherrard720251993
Geneseo620251967
Duncan Mills620251994
Payson620252000
Lake Summerset620252001
Union620172001
Caledonia520251993
Camp Point520251993
Eldred520251993
Guilford420231967
Itasca420251973
Wayne420241966
Gulfport420251971
Monica420171973
Deer Creek420241967
Humboldt420211972
Mt Vernon420141972

Baltimore Oriole Population Trend in Other States

alabamaarkansascaliforniacoloradoconnecticutdelawaregeorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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