BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Yellow-throated Vireo Population Trend in Illinois

All statesForest birds

Yellow-throated Vireo in Illinois has surged: up 619% on the route-weighted index since 1969.

+619%Since 1969TrendPercent 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 →
87Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-throated Vireo 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 →

Yellow-throated Vireo has surged in Illinois: up 619% on the route-weighted index since 1969.

Yellow-throated Vireo Population Forecast in Illinois

If the recent trend holds, Yellow-throated Vireo in Illinois is projected to stay roughly flat through 2029, near 0.71 (95% range 0.41–1.0). A 5-year backtest shows a typical error of ±30%, with 60% 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 →
0.71Projected 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 →
0.41–1.095% 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 →
±30%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, Yellow-throated Vireo in Illinois is projected to stay roughly flat through 2029, near 0.71 (95% range 0.41–1.0). A 5-year backtest shows a typical error of ±30%, with 60% 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 →
20250.680.380.97
20260.680.390.98
20270.690.400.98
20280.700.410.99
20290.710.411.0

Yellow-throated Vireo Survey Routes in Illinois

Routes recording Yellow-throated Vireo 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 →
Beaverdam Lk620231970
Sandusky620231993
Delwood520241970
Clayton520232021
Geneseo420001971
Belleview420241970
St Morgan420221970
Camp Point420231996
York420242000
Stillwell320231989
Beaucoup320241989
Pulaski320241970
Bremen320241969
Belknap320241970
Robinson320231994
Darmstadt320242014
Cave In Rock320241993
Dudleyville320242001
Guilford220231969
Sheffield220241970
Streator220211981
Wayne220231969
Chandlervill220001985
Monica220151999
Mt Vernon220241975

Yellow-throated Vireo Population Trend in Other States

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

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