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Species · Illinois · BBS 2026 Release · 1966–2025

Western Meadowlark Population Trend in Illinois

All statesGrassland birds

Western Meadowlark in Illinois has collapsed: down 98% on the route-weighted index since 1968.

-98%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 →
68Routes 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 Western Meadowlark 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 →

Western Meadowlark has collapsed in Illinois: down 98% on the route-weighted index since 1968.

Western Meadowlark Population Forecast in Illinois

If the recent trend holds, Western Meadowlark in Illinois is projected to fall about 100% by 2030 — from 0.25 in 2025 to a central estimate of 0.00 (95% range 0.00–4.0). A 5-year backtest shows a typical error of ±607%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–4.095% 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 →
±607%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, Western Meadowlark in Illinois is projected to fall about 100% by 2030 — from 0.25 in 2025 to a central estimate of 0.00 (95% range 0.00–4.0). A 5-year backtest shows a typical error of ±607%, 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 →
20260.000.004.0
20270.000.004.0
20280.000.004.0
20290.000.004.0
20300.000.004.0

Western Meadowlark Survey Routes in Illinois

Routes recording Western Meadowlark 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 →
Cherry Val1320021972
Atkinson620241966
Williamsfld620191973
Troy Grove620251993
Mill Creek520191966
Buda520231979
Fairbury420041976
Keithsburg420252001
Geneseo320171967
Newark320221969
Cameron320251966
Shannon320161993
Le Roy320001998
Darmstadt320062006
Holcomb220171971
Streator220251972
Sherburnvill220131967
Dailey220171992
Bluff Spgs220221982
Athensville219771971
Concord219711970
Pawnee219711968
Clarksdale219711968
Lake Summerset220192001
Mascoutah Lk220241967

Western Meadowlark Population Trend in Other States

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