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

Northern Rough-winged Swallow Population Trend in Vermont

All statesAerial insectivores

Northern Rough-winged Swallow in Vermont has increased: up 34% on the route-weighted index since 1969.

+34%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 →
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 →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Rough-winged 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 →

No notable trend signals for Northern Rough-winged Swallow in Vermont. See the full index history below.

Northern Rough-winged Swallow Population Forecast in Vermont

If the recent trend holds, Northern Rough-winged Swallow in Vermont is projected to rise about 543% by 2028 — from 0.06 in 2023 to a central estimate of 0.36 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±176.4%, with 100% of held-out values landing inside the 95% band.

+543%Change by 2028TrendPercent 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 →
0.36Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.195% 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 →
±176.4%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, Northern Rough-winged Swallow in Vermont is projected to rise about 543% by 2028 — from 0.06 in 2023 to a central estimate of 0.36 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±176.4%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.350.001.0
20250.360.001.0
20260.360.001.0
20270.360.001.0
20280.360.001.1

Northern Rough-winged Swallow Survey Routes in Vermont

Routes recording Northern Rough-winged 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 →
Shaftsbury2520041975
Grand Isle820101980
Middlesex719861972
Colchester520222022
S Wallingfrd420171998
Stowe419951991
W Rutland320221973
Landgrove220212018
Gaysville220021966
St Johnsbury220022002
East Haven219881985
Northfld Fls219911991
Greensboro219891967
Marlboro119771966
North Pownal120111969
Stratton119781966
S Reading120231972
Post Mills120111975
East Calais120091979
Newbury119981998
Hardwick119911980
Waterville119791979
Hinesburg119921978
Bristol120132013

Northern Rough-winged 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 2026-05-22.