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Species · Illinois · BBS 2025 Release · 1966–2024

Downy Woodpecker Population Trend in Illinois

All statesForest birds

Downy Woodpecker in Illinois has surged: up 92% on the route-weighted index since 1968.

+92%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 Downy Woodpecker 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 →

Downy Woodpecker has surged in Illinois: up 92% on the route-weighted index since 1968.

Downy Woodpecker Population Forecast in Illinois

If the recent trend holds, Downy Woodpecker in Illinois is projected to stay roughly flat through 2029, near 2.1 (95% range 1.5–2.7). A 5-year backtest shows a typical error of ±17.2%, with 80% of held-out values landing inside the 95% band.

-7%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 →
2.1Projected 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 →
1.5–2.795% 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 →
±17.2%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, Downy Woodpecker in Illinois is projected to stay roughly flat through 2029, near 2.1 (95% range 1.5–2.7). A 5-year backtest shows a typical error of ±17.2%, with 80% 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 →
20252.11.52.7
20262.11.52.7
20272.11.52.7
20282.11.52.7
20292.11.52.7

Downy Woodpecker Survey Routes in Illinois

Routes recording Downy Woodpecker 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 →
Bremen1120241969
Wayne920241967
Pulaski920241971
Royalton920242001
Belleview820241966
Delwood820241970
Beaverdam Lk820231970
Sheffield720241966
Monica720161974
St Morgan720221967
Duncan Mills620241993
Chandlervill520241971
Birds520241977
Cave In Rock520241993
Union520172001
Itasca420241966
New Lenox420191969
Deer Creek420241966
Melrose419991973
Concord420241967
Beaucoup420241972
Mt Vernon420241971
Belknap420241970
Athens420241995
Geneseo320211967

Downy Woodpecker Population Trend in Other States

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

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