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

Bobolink In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionGrassland birds

Bobolink 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 →
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 →
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 →

Bobolink has collapsed in Prairie Hardwood Transition: down 85% 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 2030 — from 2.4 in 2025 to a central estimate of 0.00 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±52.2%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–4.495% 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 →
±52.2%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 2030 — from 2.4 in 2025 to a central estimate of 0.00 (95% range 0.00–4.4). A 5-year backtest shows a typical error of ±52.2%, 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 →
20260.900.005.3
20270.620.005.0
20280.340.004.7
20290.060.004.4
20300.000.004.4

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
Chatfield 2MINNESOTA162025
StetsonvilleWISCONSIN152025
Buena VistaWISCONSIN152025
HungerfordMICHIGAN132025
StratfordWISCONSIN132025
Lake GalenaILLINOIS122021
BismarkOHIO121995
EdenWISCONSIN122025
Big RapidsMICHIGAN111990
EvergreenMINNESOTA112025
TyreMICHIGAN101996
KielWISCONSIN102022
PettysvilleMICHIGAN91979
HudsonWISCONSIN92025
WeyerhauserWISCONSIN92025
Stevens PtWISCONSIN92023
Packertown 2INDIANA82025
Drayton PlnsMICHIGAN81987
Allegan WmaMICHIGAN82019
Brook ParkMINNESOTA82025
Whitewater 2MINNESOTA82019

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