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Species · Indiana · BBS 2025 Release · 1966–2024

Bell's Vireo Population Trend in Indiana

All statesForest birds

Bell's Vireo in Indiana has surged: up 255% on the route-weighted index since 1975.

+255%Since 1975TrendPercent 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 →
18Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bell's Vireo Trends in IndianaNotable 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 →

Bell's Vireo has surged in Indiana: up 255% on the route-weighted index since 1975.

Bell's Vireo Population Forecast in Indiana

If the recent trend holds, Bell's Vireo in Indiana is projected to rise about 40% by 2029 — from 0.16 in 2024 to a central estimate of 0.23 (95% range 0.10–0.36). A 5-year backtest shows a typical error of ±35.2%, with 80% of held-out values landing inside the 95% band.

+40%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 →
0.23Projected 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 →
0.10–0.3695% 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 →
±35.2%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, Bell's Vireo in Indiana is projected to rise about 40% by 2029 — from 0.16 in 2024 to a central estimate of 0.23 (95% range 0.10–0.36). A 5-year backtest shows a typical error of ±35.2%, with 80% of held-out values landing inside the 95% band.19692029
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 →
20250.210.090.34
20260.220.090.35
20270.220.100.35
20280.230.100.35
20290.230.100.36

Bell's Vireo Survey Routes in Indiana

Routes recording Bell's Vireo in Indiana.
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 →
Millersburg420141986
Pimento420241990
Wallace220232023
New Castle220222021
Washington120242017
Gary119841984
Hebron119751969
Indian Spgs120232021
Kewanna119931993
Newberry120242010
Kankakee Sands120242002
Fowler120102010
Evansville120191978
Monticello119881988
Cuba120172017
Brazil120242012
Friendswood120242023
Jamestown119911991

Bell's Vireo Population Trend in Other States

arizonaarkansascaliforniacoloradoillinoisiowakansaskentuckymichiganminnesotamissourinebraskanevadanew-mexiconorth-dakotaohiooklahomasouth-dakotatexasutahwisconsin

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