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

Savannah Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Savannah Sparrow in Eastern Tallgrass Prairie has collapsed: down 79% on the route-weighted index since 1968.

-79%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 →
172Routes 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 →

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 79% 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 15% by 2029 — from 0.68 in 2024 to a central estimate of 0.58 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±30.3%, with 100% of held-out values landing inside the 95% band.

-15%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 →
0.58Projected 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 →
0.00–1.895% 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 →
±30.3%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, Savannah Sparrow in Eastern Tallgrass Prairie is projected to fall about 15% by 2029 — from 0.68 in 2024 to a central estimate of 0.58 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±30.3%, 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 →
20250.740.001.9
20260.700.001.9
20270.660.001.9
20280.620.001.8
20290.580.001.8

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 →
RaymondWISCONSIN292024
ClaytonILLINOIS242019
NewportOHIO201994
CosmosOHIO151999
Ash CreekMINNESOTA122024
Witts StationINDIANA102024
HarristownILLINOIS92019
MuncieINDIANA91997
TecumsehOHIO91982
Cedar ValleyIOWA81997
River FallsWISCONSIN82024
AldenILLINOIS72023
W CarrolltonOHIO72008
OlneyILLINOIS61970
Troy GroveILLINOIS62012
FrontenacMINNESOTA62023
KunkleOHIO62024
RobinsonILLINOIS52023
ExlineIOWA52006
PiersonIOWA52012
GeneseoILLINOIS42021
CaledoniaILLINOIS42024
JamestownINDIANA42024
KokomoINDIANA42024
CubaINDIANA42021

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