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

Field Sparrow Population Trend in Indiana

All statesGeneralists

Field Sparrow in Indiana has fallen sharply: down 55% on the route-weighted index since 1968.

-55%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 →
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 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 55% 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 40% by 2029 — from 9.3 in 2024 to a central estimate of 5.6 (95% range 0.60–11). A 5-year backtest shows a typical error of ±36.7%, with 100% 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 →
5.6Projected 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 →
0.60–1195% 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 →
±36.7%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 40% by 2029 — from 9.3 in 2024 to a central estimate of 5.6 (95% range 0.60–11). A 5-year backtest shows a typical error of ±36.7%, 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 →
20256.31.311
20266.11.211
20275.90.9711
20285.80.7911
20295.60.6011

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 Sands2120242000
Thorntown1920241982
Spencer1820241967
Sexton1720241981
Vevay1620241966
Knox1520241981
Newberry1520241999
Wallace1420241999
Jamestown1320241986
Indian Spgs1320241982
Packertown1220041967
Brookville1220241966
Celestine1220241979
New Phila1220241982
Scottsburg1220241982
Georgia1220241999
Pimento1120241981
Clear Spring1120241981
W Lafayette1020241981
Shelbyville1020241983
Montpelier1020242018
Wabash920241981
Brazil920241966

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 2026-05-22.