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

Vesper Sparrow Population Trend in Vermont

All statesGrassland birds

Vesper Sparrow in Vermont has collapsed: down 88% on the route-weighted index since 1969.

-88%Since 1969TrendPercent 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 →
18Routes 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 →
29YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Vesper Sparrow 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 →

Vesper Sparrow has collapsed in Vermont: down 88% on the route-weighted index since 1969.

Vesper Sparrow Population Forecast in Vermont

If the recent trend holds, Vesper Sparrow in Vermont is projected to fall about 100% by 2019 — from 0.06 in 2014 to a central estimate of 0.00 (95% range 0.00–0.42). A 5-year backtest shows a typical error of ±65.6%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2019TrendPercent 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 2019 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4295% 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 →
±65.6%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, Vesper Sparrow in Vermont is projected to fall about 100% by 2019 — from 0.06 in 2014 to a central estimate of 0.00 (95% range 0.00–0.42). A 5-year backtest shows a typical error of ±65.6%, with 100% of held-out values landing inside the 95% band.19672019
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 →
20150.000.000.42
20160.000.000.42
20170.000.000.42
20180.000.000.42
20190.000.000.42

Vesper Sparrow Survey Routes in Vermont

Routes recording Vesper Sparrow 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 →
Fletcher719851969
Shaftsbury419671967
Grand Isle419871967
East Haven319921970
Gaysville219781978
Greensboro220001968
North Pownal119761967
S Reading119821970
Post Mills119811967
S Wallingfrd120141967
St Johnsbury119981970
Northfld Fls119801980
Middlesex119861969
Hardwick119921970
Waterville119801968
Hinesburg119881970
Colchester119981998
Bristol120122012

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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