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

Swamp Sparrow Population Trend in Vermont

All statesGeneralists

Swamp Sparrow in Vermont has increased: up 28% on the route-weighted index since 1968.

+28%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 →
24Routes 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 Swamp 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 →

No notable trend signals for Swamp Sparrow in Vermont. See the full index history below.

Swamp Sparrow Population Forecast in Vermont

If the recent trend holds, Swamp Sparrow in Vermont is projected to stay roughly flat through 2029, near 2.1 (95% range 0.78–3.5). A 5-year backtest shows a typical error of ±54.5%, with 100% of held-out values landing inside the 95% band.

+1%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 →
2.1Projected 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 →
0.78–3.595% 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 →
±54.5%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, Swamp Sparrow in Vermont is projected to stay roughly flat through 2029, near 2.1 (95% range 0.78–3.5). A 5-year backtest shows a typical error of ±54.5%, 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 →
20252.10.753.4
20262.10.763.5
20272.10.773.5
20282.10.783.5
20292.10.783.5

Swamp Sparrow Survey Routes in Vermont

Routes recording Swamp 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 →
Hinesburg1419941977
W Rutland1320241966
Hardwick920241966
Stowe620241989
S Wallingfrd320221966
Marlboro219671967
Landgrove220241970
East Haven220231966
Middlesex220241968
East Calais220241966
Waterville219801979
Grand Isle220231967
North Pownal120241967
Stratton120231966
S Reading120221969
Post Mills120241967
Shaftsbury120241973
St Johnsbury119981973
Northfld Fls120181980
Greensboro120241967
Fletcher120111993
Colchester120221999
Newbury 2120152009
Bristol120181995

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisindianaiowamainemarylandmassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandsouth-dakotavirginiawest-virginiawisconsin

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