BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Song Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Song Sparrow in Boreal Hardwood Transition has declined: down 43% on the route-weighted index since 1968.

-43%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 →
127Routes 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 Song Sparrow in Boreal Hardwood Transition. See the full index history below.

Forecast

If the recent trend holds, Song Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 14 (95% range 8.1–21). A 5-year backtest shows a typical error of ±29.7%, with 80% of held-out values landing inside the 95% band.

-8%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 →
14Projected 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 →
8.1–2195% 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, Song Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 14 (95% range 8.1–21). A 5-year backtest shows a typical error of ±29.7%, 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 →
2025158.821
2026158.621
2027158.521
2028158.321
2029148.121

Routes In Boreal Hardwood Transition

Routes recording Song 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 →
Amnicon FallsWISCONSIN602024
GilmanWISCONSIN582024
PickfordMICHIGAN532024
BagleyMINNESOTA502006
BayfieldWISCONSIN462024
Pleasant Valley 2MICHIGAN372024
RiggsvilleMICHIGAN362019
Maple GroveMICHIGAN322024
FloodwoodMINNESOTA322024
OntonagonMICHIGAN312019
DebsMINNESOTA302024
MahtowaMINNESOTA302023
BrainerdMINNESOTA302024
GreenbushMINNESOTA302024
Wigwam BayMINNESOTA292023
MellenWISCONSIN292024
Nett LakeMINNESOTA282024
IrmaWISCONSIN272024
Weirgor SpringsWISCONSIN272024
Crane LakeMINNESOTA262024
Little ForkMINNESOTA262024
LudeMINNESOTA252023
HermanMICHIGAN242022
WilsonMICHIGAN242010
Pleasant ValMICHIGAN241997

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