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

Field Sparrow Population Trend in Indiana

All statesForest birds

Field Sparrow in Indiana has fallen sharply: down 57% on the route-weighted index since 1968.

-57%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 →
69Routes 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 Field Sparrow 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 →

Field Sparrow has fallen sharply in Indiana: down 57% on the route-weighted index since 1968.

Field Sparrow Population Forecast in Indiana

If the recent trend holds, Field Sparrow in Indiana is projected to fall about 32% by 2030 — from 8.2 in 2025 to a central estimate of 5.5 (95% range 0.58–10). A 5-year backtest shows a typical error of ±36%, with 100% of held-out values landing inside the 95% band.

-32%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 →
5.5Projected 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 →
0.58–1095% 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 →
±36%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, Field Sparrow in Indiana is projected to fall about 32% by 2030 — from 8.2 in 2025 to a central estimate of 5.5 (95% range 0.58–10). A 5-year backtest shows a typical error of ±36%, 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 →
20266.31.311
20276.11.111
20285.90.9411
20295.70.7611
20305.50.5810

Field Sparrow Survey Routes in Indiana

Routes recording Field Sparrow 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 →
New Castle4520242002
Ellis3820241966
Kankakee Sands2620252000
Newberry2320251999
Brookville2120251966
Witts Station2020252000
Spencer1820241967
Sexton1720241981
Knox1620251981
Azalia1620251982
New Phila1620251982
Cyprss1620251999
Scottsburg1420251982
Wallace1420241999
Thorntown1320251982
Indian Spgs1320251982
Packertown1220041967
Georgia1120251999
Galveston1020251981
Pimento1020251981
Shelbyville1020251983
Montpelier1020242018
Brazil920251966
Friendswood920241986
Millersburg920241981

Field Sparrow Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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