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

Vesper Sparrow Population Trend in Indiana

All statesGrassland birds

Vesper Sparrow in Indiana has collapsed: down 88% on the route-weighted index since 1968.

-88%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 →
58Routes 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 Vesper 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 →

Vesper Sparrow has collapsed in Indiana: down 88% on the route-weighted index since 1968.

Vesper Sparrow Population Forecast in Indiana

If the recent trend holds, Vesper Sparrow in Indiana is projected to stay roughly flat through 2029, near 1.2 (95% range 0.00–5.2). A 5-year backtest shows a typical error of ±62.8%, with 100% of held-out values landing inside the 95% band.

+3%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 →
1.2Projected 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 →
0.00–5.295% 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 →
±62.8%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, Vesper Sparrow in Indiana is projected to stay roughly flat through 2029, near 1.2 (95% range 0.00–5.2). A 5-year backtest shows a typical error of ±62.8%, 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 →
20251.80.005.8
20261.70.005.7
20271.50.005.5
20281.40.005.3
20291.20.005.2

Vesper Sparrow Survey Routes in Indiana

Routes recording Vesper 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 →
Kewanna2220221981
Sexton1820161983
Monticello1320241981
Packertown1119931967
W Lafayette1020241981
Tipton819921966
Maplewood820212017
Laporte820231999
Galveston520241981
Hebron420221966
Fowler420241966
Brazil420171966
Frankfort420221999
Jamestown320241986
Spencer320211970
Montpelier320242018
Decatur320192002
Portage 2320222015
Portage320002000
Lakeville320242011
Columbia Cty220241981
Thorntown220241982
Wabash220241983
Berne220241966
Cumback220041966

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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