BirdAnalyst
Species · BCR 22 · BBS 2026 Release · 1966–2025

Savannah Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Savannah Sparrow in Eastern Tallgrass Prairie has collapsed: down 78% on the route-weighted index since 1968.

-78%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 →
175Routes 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 →
59YearsYears 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 →

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 →

Savannah Sparrow has collapsed in Eastern Tallgrass Prairie: down 78% on the route-weighted index since 1968.

Savannah Sparrow In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Savannah Sparrow in Eastern Tallgrass Prairie is projected to fall about 31% by 2030 — from 0.78 in 2025 to a central estimate of 0.54 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±29.7%, with 100% of held-out values landing inside the 95% band.

-31%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 →
0.54Projected 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 →
0.00–1.795% 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 →
±29.7%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, Savannah Sparrow in Eastern Tallgrass Prairie is projected to fall about 31% by 2030 — from 0.78 in 2025 to a central estimate of 0.54 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±29.7%, 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 →
20260.710.001.9
20270.670.001.9
20280.620.001.8
20290.580.001.8
20300.540.001.7

Routes In Eastern Tallgrass Prairie

Routes recording Savannah 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 →
ClaytonILLINOIS242019
RaymondWISCONSIN232025
NewportOHIO201994
CosmosOHIO151999
CubaINDIANA112025
River FallsWISCONSIN112025
Witts StationINDIANA102025
HarristownILLINOIS92019
MuncieINDIANA91997
JamestownINDIANA92025
TecumsehOHIO91982
CaledoniaILLINOIS82025
Cedar ValleyIOWA81997
Ash CreekMINNESOTA72025
W CarrolltonOHIO72008
OlneyILLINOIS61970
Troy GroveILLINOIS62012
MilroyINDIANA62025
FrontenacMINNESOTA62023
KunkleOHIO62025
WayneILLINOIS52025
RobinsonILLINOIS52023
ExlineIOWA52006
PiersonIOWA52012
No KentonOHIO52025

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