BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Ruby-throated Hummingbird Population Trend in Illinois

All statesGeneralists

Ruby-throated Hummingbird in Illinois has surged: up 14× on the route-weighted index since 1968.

14×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 →
58YearsYears 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 14× 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 stay roughly flat through 2029, near 0.88 (95% range 0.57–1.2). A 5-year backtest shows a typical error of ±15.2%, with 100% of held-out values landing inside the 95% band.

-3%Change by 2029TrendPercent 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 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.57–1.295% 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 →
±15.2%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 stay roughly flat through 2029, near 0.88 (95% range 0.57–1.2). A 5-year backtest shows a typical error of ±15.2%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.830.521.1
20260.840.541.1
20270.850.551.2
20280.870.561.2
20290.880.571.2

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 →
Belleview1020241966
Royalton820242001
Pulaski720241970
Belknap620241970
Mt Vernon520221971
Cave In Rock520241993
Marshall520242001
Beaverdam Lk320221970
Newark220212001
Gulfport220242002
Milford219891989
Athensville220161971
Bradbury220241971
St Morgan220221968
Olney220241969
Bremen220241970
Robinson220231972
Caledonia220231993
Sherrard220091995
Camp Point220241996
Eldred220211994
Nilwood220232008
York220221993
Darmstadt220221993
Sandusky220231993

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 2026-05-22.