BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Sora In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

Sora in Prairie Hardwood Transition has collapsed: down 79% on the route-weighted index since 1968.

-79%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 →
88Routes 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 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 collapsed in Prairie Hardwood Transition: down 79% on the route-weighted index since 1968.

Sora In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Sora in Prairie Hardwood Transition is projected to fall about 17% by 2029 — from 0.09 in 2024 to a central estimate of 0.07 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±225.4%, with 100% of held-out values landing inside the 95% band.

-17%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 →
0.07Projected 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 →
0.00–0.2695% 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 →
±225.4%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 Prairie Hardwood Transition is projected to fall about 17% by 2029 — from 0.09 in 2024 to a central estimate of 0.07 (95% range 0.00–0.26). A 5-year backtest shows a typical error of ±225.4%, 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 →
20250.080.000.27
20260.080.000.27
20270.080.000.27
20280.070.000.27
20290.070.000.26

Routes In Prairie Hardwood Transition

Routes recording Sora in Prairie 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 →
OsseoMINNESOTA32019
New LondonMINNESOTA32024
GlenwoodMINNESOTA32019
AshbyMINNESOTA32019
DresserWISCONSIN32017
MerrillWISCONSIN31973
MinnetonkaMINNESOTA22024
KnappMINNESOTA22019
Sherburne NrMINNESOTA22024
HudsonWISCONSIN21996
HolwayWISCONSIN21978
Stevens PtWISCONSIN22019
Oconto FallsWISCONSIN22004
OmroWISCONSIN21996
BrownsvilleWISCONSIN21975
Buena VistaWISCONSIN22014
PackertownINDIANA11983
EllisINDIANA11983
Indiana DuneINDIANA12009
FestinaIOWA11975
ScottvilleMICHIGAN11974
Big Blue LkMICHIGAN12015
Big RapidsMICHIGAN11986
NashvilleMICHIGAN12015
CoopersvilleMICHIGAN12021

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