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

Bobolink In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGrassland birds

Bobolink in Prairie Hardwood Transition has collapsed: down 84% on the route-weighted index since 1968.

-84%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 →
155Routes 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 →

Bobolink has collapsed in Prairie Hardwood Transition: down 84% on the route-weighted index since 1968.

Bobolink In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Bobolink in Prairie Hardwood Transition is projected to fall about 100% by 2029 — from 1.9 in 2024 to a central estimate of 0.00 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±43.9%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–4.495% 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 →
±43.9%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, Bobolink in Prairie Hardwood Transition is projected to fall about 100% by 2029 — from 1.9 in 2024 to a central estimate of 0.00 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±43.9%, 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 →
20251.10.005.5
20260.800.005.2
20270.520.004.9
20280.240.004.6
20290.000.004.4

Routes In Prairie Hardwood Transition

Routes recording Bobolink 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 →
HolwayWISCONSIN531989
Wis RapidsWISCONSIN252023
OmroWISCONSIN232001
GuilfordILLINOIS172023
HungerfordMICHIGAN152024
Lake GalenaILLINOIS122021
OlaMICHIGAN122024
BismarkOHIO121995
Big RapidsMICHIGAN111990
Buena VistaWISCONSIN112024
TyreMICHIGAN101996
WeyerhauserWISCONSIN102024
KielWISCONSIN102022
PettysvilleMICHIGAN91979
Chatfield 2MINNESOTA92024
HudsonWISCONSIN92024
Stevens PtWISCONSIN92023
ColbyWISCONSIN92024
Drayton PlnsMICHIGAN81987
Allegan WmaMICHIGAN82019
Whitewater 2MINNESOTA82019
GraytownOHIO81984
LakevilleINDIANA72003
Packertown 2INDIANA72024
Maple RapidsMICHIGAN72019

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