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

Henslow's Sparrow Population Trend in Indiana

All statesGrassland birds

Henslow's Sparrow in Indiana has fallen sharply: down 73% on the route-weighted index since 1968.

-73%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 →
32Routes 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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Henslow's 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 →

Henslow's Sparrow has fallen sharply in Indiana: down 73% on the route-weighted index since 1968.

Henslow's Sparrow Population Forecast in Indiana

If the recent trend holds, Henslow's Sparrow in Indiana is projected to rise about 238% by 2029 — from 0.11 in 2024 to a central estimate of 0.37 (95% range 0.00–0.79). A 5-year backtest shows a typical error of ±232%, with 100% of held-out values landing inside the 95% band.

+238%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 →
0.37Projected 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 →
0.00–0.7995% 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 →
±232%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, Henslow's Sparrow in Indiana is projected to rise about 238% by 2029 — from 0.11 in 2024 to a central estimate of 0.37 (95% range 0.00–0.79). A 5-year backtest shows a typical error of ±232%, 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 →
20250.360.000.78
20260.360.000.78
20270.360.000.78
20280.370.000.79
20290.370.000.79

Henslow's Sparrow Survey Routes in Indiana

Routes recording Henslow's 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 →
Packertown419701967
Kankakee Sands320242002
Celestine319891983
Clear Spring320131994
Hebron219661966
W Lafayette220242022
Brookville219731966
Vevay219871966
Newberry220152015
Georgia220182005
Cross Plains220231999
Knox119961996
Ellis120001966
Fowler120221966
Monticello120232003
Tipton119721972
Muncie119861986
Pimento120162000
Brazil119661966
Spencer120111970
Sexton120072007
Milroy119911967
Shelbyville119911991
Millersburg120002000
Indian Spgs120191996

Henslow's Sparrow Population Trend in Other States

delawareillinoisiowakansaskentuckymarylandmichiganminnesotamissourinebraskanew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-dakotavermontvirginiawest-virginiawisconsin

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