BirdAnalyst
Species · Vermont · BBS 2026 Release · 1966–2025

Barn Swallow Population Trend in Vermont

All statesAerial insectivores

Barn Swallow in Vermont has fallen sharply: down 72% on the route-weighted index since 1968.

-72%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 →
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 Barn Swallow 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 →

Barn Swallow has fallen sharply in Vermont: down 72% on the route-weighted index since 1968.

Barn Swallow Population Forecast in Vermont

If the recent trend holds, Barn Swallow in Vermont is projected to fall about 100% by 2030 — from 8.6 in 2025 to a central estimate of 0.00 (95% range 0.00–8.7). A 5-year backtest shows a typical error of ±130.1%, with 60% 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 →
0.00–8.795% 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 →
±130.1%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, Barn Swallow in Vermont is projected to fall about 100% by 2030 — from 8.6 in 2025 to a central estimate of 0.00 (95% range 0.00–8.7). A 5-year backtest shows a typical error of ±130.1%, with 60% 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 →
20260.000.008.7
20270.000.008.7
20280.000.008.7
20290.000.008.7
20300.000.008.7

Barn Swallow Survey Routes in Vermont

Routes recording Barn Swallow 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 →
Waterville4219801967
Bristol3720251995
Hinesburg3319941966
Fletcher2220251968
Colchester2120251986
Shaftsbury1420251966
North Pownal1320251966
Hardwick1220241966
Northfld Fls1020251980
Stratton820251966
W Rutland820251966
Gaysville620211966
St Johnsbury520251970
East Haven520251966
Greensboro520251967
Marlboro420251966
Stowe420241988
Grand Isle320241967
Landgrove220251966
S Reading220241966
S Wallingfrd220211966
Newbury220041986
Post Mills120251966
Middlesex120241968
East Calais120231966

Barn Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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