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Species · BCR 12 · BBS 2026 Release · 1966–2025

Savannah Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGrassland birds

Savannah Sparrow in Boreal Hardwood Transition has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
106Routes 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 fallen sharply in Boreal Hardwood Transition: down 61% on the route-weighted index since 1968.

Savannah Sparrow In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Savannah Sparrow in Boreal Hardwood Transition is projected to rise about 15% by 2030 — from 4.8 in 2025 to a central estimate of 5.5 (95% range 1.2–9.9). A 5-year backtest shows a typical error of ±97%, with 60% of held-out values landing inside the 95% band.

+15%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 →
5.5Projected 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 →
1.2–9.995% 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 →
±97%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 Boreal Hardwood Transition is projected to rise about 15% by 2030 — from 4.8 in 2025 to a central estimate of 5.5 (95% range 1.2–9.9). A 5-year backtest shows a typical error of ±97%, with 60% 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 →
20266.01.610
20275.91.510
20285.81.410
20295.71.310
20305.51.29.9

Routes In Boreal Hardwood Transition

Routes recording Savannah Sparrow in Boreal 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 →
PickfordMICHIGAN1062025
Iron RiverWISCONSIN372025
BayfieldWISCONSIN342025
WarroadMINNESOTA292025
Amnicon FallsWISCONSIN272025
GreenbushMINNESOTA232025
DebsMINNESOTA182025
Hubbard LakeMICHIGAN161996
Nett LakeMINNESOTA162024
OntonagonMICHIGAN132019
ChaffeyWISCONSIN122025
CathroMICHIGAN92016
HerronMICHIGAN92016
BerglandMICHIGAN81990
Little ForkMINNESOTA82024
MahtowaMINNESOTA82023
BootjackMICHIGAN72023
RiggsvilleMICHIGAN72019
FloodwoodMINNESOTA72025
LudeMINNESOTA72025
GilmanWISCONSIN72025
Lake CityMICHIGAN62022
Cedar RunMICHIGAN61999
Walloon Lake 2MICHIGAN62018
Walloon LakeMICHIGAN52004

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