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Species · Illinois · BBS 2026 Release · 1966–2025

Ruby-throated Hummingbird Population Trend in Illinois

All statesForest birds

Ruby-throated Hummingbird in Illinois has surged: up 13× on the route-weighted index since 1968.

13×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 →
95Routes 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 Ruby-throated Hummingbird 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 →

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 →

Ruby-throated Hummingbird has surged in Illinois: up 13× on the route-weighted index since 1968.

Ruby-throated Hummingbird Population Forecast in Illinois

If the recent trend holds, Ruby-throated Hummingbird in Illinois is projected to rise about 16% by 2030 — from 0.76 in 2025 to a central estimate of 0.88 (95% range 0.58–1.2). A 5-year backtest shows a typical error of ±14.2%, with 100% of held-out values landing inside the 95% band.

+16%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 →
0.88Projected 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 →
0.58–1.295% 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 →
±14.2%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, Ruby-throated Hummingbird in Illinois is projected to rise about 16% by 2030 — from 0.76 in 2025 to a central estimate of 0.88 (95% range 0.58–1.2). A 5-year backtest shows a typical error of ±14.2%, 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 →
20260.840.531.1
20270.850.541.2
20280.860.561.2
20290.870.571.2
20300.880.581.2

Ruby-throated Hummingbird Survey Routes in Illinois

Routes recording Ruby-throated Hummingbird 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 →
Pulaski820251970
Cave In Rock520241993
Belleview420251966
Concord320251970
Bradbury320251971
Bremen320251970
Delwood320251970
Beaverdam Lk320221970
York320251993
Marshall320252001
Royalton320252001
Newark220212001
Gulfport220242002
Milford219891989
Martinsville220251972
Jamestown220251971
St Morgan220221968
Olney220241969
Belknap220251970
Robinson220231972
Caledonia220231993
Sherrard220091995
Camp Point220251996
Eldred220211994
Nilwood220232008

Ruby-throated Hummingbird Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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