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

Lark Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGrassland birds

Lark Sparrow in Boreal Hardwood Transition has surged: up 78% on the route-weighted index since 1985.

+78%Since 1985TrendPercent 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 →
8Routes 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 →
21YearsYears 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 Lark Sparrow in Boreal Hardwood Transition. See the full index history below.

Lark Sparrow In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Lark Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2030, near 0.05 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±169%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.05Projected 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 →
0.00–0.1095% 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 →
±169%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, Lark Sparrow in Boreal Hardwood Transition is projected to stay roughly flat through 2030, near 0.05 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±169%, with 100% of held-out values landing inside the 95% band.19832030
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 →
20260.050.000.10
20270.050.000.10
20280.050.000.10
20290.050.000.10
20300.050.000.10

Routes In Boreal Hardwood Transition

Routes recording Lark 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 →
Union TwpWISCONSIN32025
LudeMINNESOTA11988
NebishMINNESOTA11995
Tamarac NwrMINNESOTA11992
MinongWISCONSIN12011
Grand ViewWISCONSIN11994
MontrealWISCONSIN11984
BashawWISCONSIN12023

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