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Species · Illinois · BBS 2025 Release · 1966–2024

Eastern Whip-poor-will Population Trend in Illinois

All statesAerial insectivores

Eastern Whip-poor-will in Illinois has fallen sharply: down 68% on the route-weighted index since 1968.

-68%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 →
55YearsYears 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 fallen sharply in Illinois: down 68% 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 2028, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±454.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 2028 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 →
±454.3%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 2028, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±454.3%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.000.000.34
20250.000.000.34
20260.000.000.34
20270.000.000.34
20280.000.000.34

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
Eldred220042004
Putnam119801976
Sheffield119931993
Stillwell119931976
Monica119901990
Mackinaw119731967
Melrose119901973
Bluff Spgs119751974
Pawnee119711971
Clarksdale119921968
Humphrey119781978
Columbia119811966
Beaucoup119711971
Mt Vernon119991972

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 2026-05-22.