BirdAnalyst
Species · BCR 23 · BBS 2026 Release · 1966–2025

Savannah Sparrow In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGrassland birds

Savannah Sparrow in Prairie Hardwood Transition has collapsed: down 85% on the route-weighted index since 1968.

-85%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 →
158Routes 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 →
59YearsYears 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 →

Savannah Sparrow has collapsed in Prairie Hardwood Transition: down 85% on the route-weighted index since 1968.

Savannah Sparrow In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Savannah Sparrow in Prairie Hardwood Transition is projected to fall about 29% by 2030 — from 4.5 in 2025 to a central estimate of 3.2 (95% range 0.00–10). A 5-year backtest shows a typical error of ±71.9%, with 100% of held-out values landing inside the 95% band.

-29%Change 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 →
3.2Projected 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 →
0.00–1095% 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 →
±71.9%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, Savannah Sparrow in Prairie Hardwood Transition is projected to fall about 29% by 2030 — from 4.5 in 2025 to a central estimate of 3.2 (95% range 0.00–10). A 5-year backtest shows a typical error of ±71.9%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20264.90.0012
20274.50.0011
20284.00.0011
20293.60.0010
20303.20.0010

Routes In Prairie Hardwood Transition

Routes recording Savannah Sparrow 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 →
HolwayWISCONSIN631989
TyreMICHIGAN501996
CascoWISCONSIN332025
StetsonvilleWISCONSIN322025
GrimmsWISCONSIN322021
BismarkOHIO261995
HamburgMICHIGAN212001
North BranchMICHIGAN201999
LapeerMICHIGAN192025
OmroWISCONSIN182001
ViroquaWISCONSIN172024
ColbyWISCONSIN172025
StratfordWISCONSIN162025
HollandWISCONSIN162025
St CharlesMICHIGAN152010
JuniataMICHIGAN142024
CohoctahMICHIGAN142025
KielWISCONSIN142025
PackertownINDIANA132004
OwendaleMICHIGAN132017
KendallWISCONSIN132025
GilmantonWISCONSIN122025
Rolling GrndWISCONSIN122025
ParisWISCONSIN122025
Chatfield 2MINNESOTA112025

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