BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Savannah Sparrow In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGrassland birds

Savannah Sparrow in Prairie Hardwood Transition has collapsed: down 85% on the route-weighted index since 1968.

-85%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 →
158Routes 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 Prairie Hardwood Transition: down 85% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Savannah Sparrow in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 3.7 (95% range 0.00–11). A 5-year backtest shows a typical error of ±86.4%, with 100% of held-out values landing inside the 95% band.

-7%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 →
3.7Projected 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 →
0.00–1195% 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 →
±86.4%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 Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 3.7 (95% range 0.00–11). A 5-year backtest shows a typical error of ±86.4%, 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 →
20255.40.0012
20265.00.0012
20274.50.0011
20284.10.0011
20293.70.0011

Routes In Prairie Hardwood Transition

Routes recording Savannah Sparrow in Prairie Hardwood Transition.
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 →
HolwayWISCONSIN631989
TyreMICHIGAN501996
GrimmsWISCONSIN322021
CascoWISCONSIN292024
BismarkOHIO261995
HamburgMICHIGAN212001
North BranchMICHIGAN201999
MiddleburyINDIANA192024
OmroWISCONSIN182001
KielWISCONSIN182022
ViroquaWISCONSIN172024
St CharlesMICHIGAN152010
StratfordWISCONSIN152024
JuniataMICHIGAN142024
LapeerMICHIGAN142024
ParisWISCONSIN142024
PackertownINDIANA132004
OwendaleMICHIGAN132017
ColbyWISCONSIN132024
CumberlandWISCONSIN112024
WeyerhauserWISCONSIN112024
AnnatonWISCONSIN112024
Chatfield 2MINNESOTA102024
CadottWISCONSIN102024
Big RapidsMICHIGAN91990

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