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Species · Illinois · BBS 2025 Release · 1966–2024

Eastern Wood-Pewee Population Trend in Illinois

All statesAerial insectivores

Eastern Wood-Pewee in Illinois has surged: up 203% on the route-weighted index since 1968.

+203%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 →
104Routes 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 Eastern Wood-Pewee 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 →

Eastern Wood-Pewee has surged in Illinois: up 203% on the route-weighted index since 1968.

Eastern Wood-Pewee Population Forecast in Illinois

If the recent trend holds, Eastern Wood-Pewee in Illinois is projected to fall about 16% by 2029 — from 5.9 in 2024 to a central estimate of 5.0 (95% range 3.3–6.6). A 5-year backtest shows a typical error of ±29.6%, with 20% of held-out values landing inside the 95% band.

-16%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 →
5.0Projected 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 →
3.3–6.695% 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 →
±29.6%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 Wood-Pewee in Illinois is projected to fall about 16% by 2029 — from 5.9 in 2024 to a central estimate of 5.0 (95% range 3.3–6.6). A 5-year backtest shows a typical error of ±29.6%, with 20% 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 →
20254.83.16.4
20264.83.26.5
20274.93.26.5
20284.93.36.6
20295.03.36.6

Eastern Wood-Pewee Survey Routes in Illinois

Routes recording Eastern Wood-Pewee 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 →
Belleview3620241966
Cave In Rock2820241993
York2420241994
Bremen1820241969
Lake Galena1820212001
Royalton1820242001
Beaverdam Lk1620231970
Eldred1520211993
Marshall1520242001
Gulfport1420231971
Athensville1420241971
Concord1420241967
Bradbury1420241970
Sheffield1320241966
St Morgan1320221967
Belknap1320241970
Delwood1320241970
Sandusky1320231993
Eubanks1220242001
Pulaski1120241970
Stillwell1020241977
Robinson1020231970
Camp Point1020241993
Birds820241976
Humphrey720241972

Eastern Wood-Pewee Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.