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

Sora In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionWetland birds

Sora in Boreal Hardwood Transition has fallen sharply: down 72% on the route-weighted index since 1968.

-72%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 →
59Routes 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 →
56YearsYears 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 →

Sora has fallen sharply in Boreal Hardwood Transition: down 72% on the route-weighted index since 1968.

Sora In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Sora in Boreal Hardwood Transition is projected to fall about 20% by 2029 — from 0.11 in 2024 to a central estimate of 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±70.9%, with 100% of held-out values landing inside the 95% band.

-20%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 →
0.09Projected 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 →
0.00–0.2795% 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 →
±70.9%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, Sora in Boreal Hardwood Transition is projected to fall about 20% by 2029 — from 0.11 in 2024 to a central estimate of 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±70.9%, 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 →
20250.090.000.27
20260.090.000.27
20270.090.000.27
20280.090.000.27
20290.090.000.27

Routes In Boreal Hardwood Transition

Routes recording Sora 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 →
BackusMINNESOTA52019
BrainerdMINNESOTA52024
CreightonMICHIGAN21993
CathroMICHIGAN22013
WaskishMINNESOTA22017
GreenbushMINNESOTA22024
Cass LakeMINNESOTA22012
ExelandWISCONSIN22017
BerglandMICHIGAN11982
MareniscoMICHIGAN12016
BootjackMICHIGAN12007
Maple GroveMICHIGAN12017
Brocky LakeMICHIGAN12017
WilsonMICHIGAN11987
CunardMICHIGAN12018
ShingletonMICHIGAN12022
Bear LakeMICHIGAN12011
TahquamenonMICHIGAN12013
Skegemog PtMICHIGAN11986
PickfordMICHIGAN12014
RiggsvilleMICHIGAN12018
OberlinMICHIGAN11974
HerronMICHIGAN12016
Seney NwrMICHIGAN12019
Scott'S MarshMICHIGAN12008

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