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

Swamp Sparrow Population Trend in Indiana

All statesWetland birds

Swamp Sparrow in Indiana has fallen sharply: down 67% on the route-weighted index since 1975.

-67%Since 1975TrendPercent 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 →
18Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Swamp 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 →

Swamp Sparrow has fallen sharply in Indiana: down 67% on the route-weighted index since 1975.

Swamp Sparrow Population Forecast in Indiana

If the recent trend holds, Swamp Sparrow in Indiana is projected to fall about 60% by 2030 — from 0.15 in 2025 to a central estimate of 0.06 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±40.9%, with 100% of held-out values landing inside the 95% band.

-60%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 →
0.06Projected 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 →
0.00–0.3495% 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 →
±40.9%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, Swamp Sparrow in Indiana is projected to fall about 60% by 2030 — from 0.15 in 2025 to a central estimate of 0.06 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±40.9%, 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 →
20260.080.000.35
20270.070.000.35
20280.070.000.34
20290.070.000.34
20300.060.000.34

Swamp Sparrow Survey Routes in Indiana

Routes recording Swamp 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 →
Indiana Dune320251994
Lagrange320091999
Gary219871980
Hebron219851970
Lakeville220232023
Packertown219931993
Portage 2220252014
South Bend119841982
Knox120252025
Portage120002000
Middlebury120251990
Ellis120231966
Crown Point120132013
Laporte120232023
Tipton119791979
Cuba120192017
Wabash120092009
Berne120242024

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisiowamainemarylandmassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandsouth-dakotavermontvirginiawest-virginiawisconsin

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