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

Bank Swallow Population Trend in Vermont

All statesAerial insectivores

Bank Swallow in Vermont has collapsed: down 93% on the route-weighted index since 1968.

-93%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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bank 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 →

Bank Swallow has collapsed in Vermont: down 93% on the route-weighted index since 1968.

Bank Swallow Population Forecast in Vermont

If the recent trend holds, Bank Swallow in Vermont is projected to fall about 100% by 2029 — from 0.33 in 2024 to a central estimate of 0.00 (95% range 0.00–8.0). A 5-year backtest shows a typical error of ±109.9%, with 100% 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 →
0.00–8.095% 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 →
±109.9%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, Bank Swallow in Vermont is projected to fall about 100% by 2029 — from 0.33 in 2024 to a central estimate of 0.00 (95% range 0.00–8.0). A 5-year backtest shows a typical error of ±109.9%, 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 →
20250.110.008.1
20260.000.008.0
20270.000.008.0
20280.000.008.0
20290.000.008.0

Bank Swallow Survey Routes in Vermont

Routes recording Bank 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 →
Hardwick2020161966
Waterville1819801967
Hinesburg1219941966
St Johnsbury620241971
East Haven619991967
Bristol520121995
Northfld Fls419911980
Marlboro319951967
North Pownal320091969
Gaysville320211966
S Wallingfrd320021980
Middlesex320101968
Stratton219991966
S Reading220021966
Post Mills220121966
Shaftsbury219961973
W Rutland220031968
Grand Isle219831969
Stowe220061990
Landgrove119821970
East Calais119931968
Greensboro120051967
Fletcher120101969
Colchester119921987

Bank Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

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