BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Swamp Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Swamp Sparrow in Eastern Tallgrass Prairie has edged down: down 15% on the route-weighted index since 1968.

-15%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 →
47Routes In RegionSurvey 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 SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Swamp Sparrow in Eastern Tallgrass Prairie. See the full index history below.

Forecast

If the recent trend holds, Swamp Sparrow in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±51.3%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.04Projected 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 →
0.00–0.0995% 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 →
±51.3%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 Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±51.3%, with 80% 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 →
20250.040.000.09
20260.040.000.09
20270.040.000.09
20280.040.000.09
20290.040.000.09

Routes In Eastern Tallgrass Prairie

Routes recording Swamp Sparrow in Eastern Tallgrass Prairie.
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 →
MilfordILLINOIS61996
Ash CreekMINNESOTA42019
WayneILLINOIS22024
GaryINDIANA21987
HebronINDIANA21985
Mill CreekILLINOIS12000
HolcombILLINOIS11998
BarringtonILLINOIS11997
ItascaILLINOIS12012
AtkinsonILLINOIS12006
SheffieldILLINOIS11974
ComptonILLINOIS12010
SherburnvillILLINOIS11992
New LenoxILLINOIS11999
ChandlervillILLINOIS11974
Mt VernonILLINOIS12005
CaledoniaILLINOIS11996
Troy GroveILLINOIS12015
AldenILLINOIS12023
Lake SummersetILLINOIS12022
UnionILLINOIS12012
TiptonINDIANA11979
WabashINDIANA12009
BerneINDIANA12024
PortageINDIANA12000

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