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

Swamp Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGeneralists

Swamp Sparrow in Boreal Hardwood Transition has surged: up 364% on the route-weighted index since 1968.

+364%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 →
119Routes 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 increasecomputed 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 →

Swamp Sparrow has surged in Boreal Hardwood Transition: up 364% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Swamp Sparrow in Boreal Hardwood Transition is projected to rise about 14% by 2029 — from 4.7 in 2024 to a central estimate of 5.3 (95% range 4.1–6.6). A 5-year backtest shows a typical error of ±24.3%, with 60% of held-out values landing inside the 95% band.

+14%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 →
5.3Projected 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 →
4.1–6.695% 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 →
±24.3%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, Swamp Sparrow in Boreal Hardwood Transition is projected to rise about 14% by 2029 — from 4.7 in 2024 to a central estimate of 5.3 (95% range 4.1–6.6). A 5-year backtest shows a typical error of ±24.3%, with 60% 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 →
20255.13.86.4
20265.23.96.4
20275.23.96.5
20285.34.06.6
20295.34.16.6

Routes In Boreal Hardwood Transition

Routes recording Swamp 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 →
GlendaleMINNESOTA382024
Crane LakeMINNESOTA232024
WaskishMINNESOTA222024
Wigwam BayMINNESOTA212023
MahtowaMINNESOTA162023
Red LakeMINNESOTA162024
Mille LacsMINNESOTA152024
Sawbill CampMINNESOTA142024
GilmanWISCONSIN142024
Hart LakeMINNESOTA132024
Sherry LakeMINNESOTA132022
BigforkMINNESOTA132024
JordanMINNESOTA122023
MuskallongeMICHIGAN112024
CromwellMINNESOTA102024
BabbittMINNESOTA102023
ChisholmMINNESOTA102024
FlambeauWISCONSIN102024
BlackduckMINNESOTA92022
Ned LakeMICHIGAN72024
Brocky LakeMICHIGAN72024
Seney NwrMICHIGAN72024
BackusMINNESOTA62024
Island LakeMINNESOTA62017
BrainerdMINNESOTA62024

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