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

Bobolink Population Trend in Indiana

All statesGrassland birds

Bobolink in Indiana has collapsed: down 95% on the route-weighted index since 1968.

-95%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 →
51Routes 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 Bobolink 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 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 →

Bobolink has collapsed in Indiana: down 95% on the route-weighted index since 1968.

Bobolink Population Forecast in Indiana

If the recent trend holds, Bobolink in Indiana is projected to fall about 100% by 2029 — from 0.18 in 2024 to a central estimate of 0.00 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±248.3%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.295% 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 →
±248.3%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, Bobolink in Indiana is projected to fall about 100% by 2029 — from 0.18 in 2024 to a central estimate of 0.00 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±248.3%, with 100% 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 →
20250.000.001.2
20260.000.001.2
20270.000.001.2
20280.000.001.2
20290.000.001.2

Bobolink Survey Routes in Indiana

Routes recording Bobolink 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 →
Corydon720061983
Lakeville720031993
Packertown 2720242005
Packertown620041967
Friendswood620001987
Columbia Cty420041982
Swayzee420031981
Jamestown320221986
Lagrange320151999
Witts Station320212000
South Bend219841966
Middletown219941966
Wabash220221981
Maplewood220002000
Shelbyville220181985
Decatur220121999
Wallace220081999
Portage220042000
Gary119881981
Hebron120101966
Knox120021981
Kewanna120071981
Middlebury120241989
Ellis120221966
Fowler120191966

Bobolink Population Trend in Other States

californiacoloradoconnecticutidahoillinoisiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotautahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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