BirdAnalyst
Species · Vermont · BBS 2025 Release · 1966–2024

Bobolink Population Trend in Vermont

All statesGrassland birds

Bobolink in Vermont has collapsed: down 78% on the route-weighted index since 1968.

-78%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 →
26Routes In StateSurvey 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 Bobolink Trends in VermontNotable 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 Vermont: down 78% on the route-weighted index since 1968.

Bobolink Population Forecast in Vermont

If the recent trend holds, Bobolink in Vermont is projected to fall about 100% by 2029 — from 4.3 in 2024 to a central estimate of 0.00 (95% range 0.00–5.5). A 5-year backtest shows a typical error of ±83.9%, with 80% 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 →
0.00–5.595% 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 →
±83.9%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 Vermont is projected to fall about 100% by 2029 — from 4.3 in 2024 to a central estimate of 0.00 (95% range 0.00–5.5). A 5-year backtest shows a typical error of ±83.9%, with 80% 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 →
20250.850.006.3
20260.510.006.0
20270.170.005.6
20280.000.005.5
20290.000.005.5

Bobolink Survey Routes in Vermont

Routes recording Bobolink in Vermont.
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 →
East Haven1520241966
Waterville1519801967
Stratton920241969
Gaysville920181966
North Pownal820241966
Greensboro820241967
Hinesburg819941966
Grand Isle820231967
Landgrove720241966
Bristol720181995
S Reading520241966
Middlesex420241968
Colchester420241986
Newbury 2420232005
Post Mills320241966
St Johnsbury320241970
Hardwick320241966
Stowe320241988
Shaftsbury220221966
W Rutland220241966
Northfld Fls220211980
Newbury220041986
Marlboro120241966
S Wallingfrd120211966
East Calais120241966

Bobolink Population Trend in Other States

californiacoloradoconnecticutidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotautahvirginiawashingtonwest-virginiawisconsinwyoming

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