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Species · Illinois · BBS 2026 Release · 1966–2025

Eastern Whip-poor-will Population Trend in Illinois

All statesAerial insectivores

Eastern Whip-poor-will in Illinois has collapsed: down 79% on the route-weighted index since 1968.

-79%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 →
37Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eastern Whip-poor-will 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 declinecomputed 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 →

Eastern Whip-poor-will has collapsed in Illinois: down 79% on the route-weighted index since 1968.

Eastern Whip-poor-will Population Forecast in Illinois

If the recent trend holds, Eastern Whip-poor-will in Illinois is projected to stay roughly flat through 2030, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±499%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.3495% 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 →
±499%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, Eastern Whip-poor-will in Illinois is projected to stay roughly flat through 2030, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±499%, 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 →
20260.000.000.34
20270.000.000.34
20280.000.000.34
20290.000.000.34
20300.000.000.34

Eastern Whip-poor-will Survey Routes in Illinois

Routes recording Eastern Whip-poor-will 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 →
Chandlervill319721972
Martinsville320191970
Robinson319731970
Yale320091996
Athens219961995
Terre Haute219841984
Deer Creek219691969
Athensville220151975
Janesville219821982
Bradbury220171982
Belknap219931970
Delwood220251970
Eldred220042004
Putnam119801976
Sheffield119931993
Stillwell119931976
Monica119901990
Mackinaw119731967
Melrose119901973
Bluff Spgs119751974
Pawnee119711971
Clarksdale119921968
Humphrey119781978
Columbia119811966
Beaucoup119711971

Eastern Whip-poor-will Population Trend in Other States

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

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