BirdAnalyst
Species · Illinois · BBS 2026 Release · 1966–2025

Killdeer Population Trend in Illinois

All statesShorebirds

Killdeer in Illinois has surged: up 637% on the route-weighted index since 1968.

+637%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 →
105Routes 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 Killdeer 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 →

Killdeer has surged in Illinois: up 637% on the route-weighted index since 1968.

Killdeer Population Forecast in Illinois

If the recent trend holds, Killdeer in Illinois is projected to rise about 27% by 2030 — from 20 in 2025 to a central estimate of 25 (95% range 21–30). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.

+27%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 →
25Projected 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 →
21–3095% 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 →
±9%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, Killdeer in Illinois is projected to rise about 27% by 2030 — from 20 in 2025 to a central estimate of 25 (95% range 21–30). A 5-year backtest shows a typical error of ±9%, 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 →
2026241928
2027242029
2028252029
2029252029
2030252130

Killdeer Survey Routes in Illinois

Routes recording Killdeer 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 →
Pontiac4720251978
Minonk4520241971
Humboldt4120251970
Stillwell3920251971
Gulfport3820251971
Sterling3820232001
Greenview3720251993
Janesville3620251973
Athensville3520251971
Harristown3520252006
Buda3420231977
Rosamond3420251972
Seneca3420251993
Yorkville3420192001
Grape Creek3420252001
Fairdale3420252019
Williamsfld3320251974
Monticello3020251978
Fairland3020251967
Martinsville2920251970
Humphrey2820251973
Le Roy2820251993
Geneseo2620251967
Chandlervill2620251971
Fairbury2520251976

Killdeer Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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