BirdAnalyst
Species · West Virginia · BBS 2026 Release · 1966–2025

Chimney Swift Population Trend in West Virginia

All statesAerial insectivores

Chimney Swift in West Virginia has fallen sharply: down 70% on the route-weighted index since 1968.

-70%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 →
63Routes 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 Chimney Swift Trends in West VirginiaNotable 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 →

Chimney Swift has fallen sharply in West Virginia: down 70% on the route-weighted index since 1968.

Chimney Swift Population Forecast in West Virginia

If the recent trend holds, Chimney Swift in West Virginia is projected to fall about 52% by 2030 — from 3.7 in 2025 to a central estimate of 1.8 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±31.5%, with 100% of held-out values landing inside the 95% band.

-52%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 →
1.8Projected 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 →
0.00–5.095% 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 →
±31.5%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, Chimney Swift in West Virginia is projected to fall about 52% by 2030 — from 3.7 in 2025 to a central estimate of 1.8 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±31.5%, with 100% 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 →
20262.30.005.5
20272.20.005.4
20282.10.005.2
20291.90.005.1
20301.80.005.0

Chimney Swift Survey Routes in West Virginia

Routes recording Chimney Swift in West Virginia.
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 →
Mcdonald4220231987
Arlee3619791966
Fayetteville2819961980
Monongah2120221966
Sleepy Creek2019901966
Bismark1920251976
Clinton1520251966
Hix1320251970
Glade Run1320021989
Hanover1220251980
Welch1220251980
Olcott1020241966
Bebee1020251972
Smoot920251980
Paradise920231966
Martinsburg920251966
Berryburg819961975
Josephs Mill820241993
Ringgold820252025
Meadland720251997
Sutton720251976
Cedarville720231982
Lost River620251996
Albright519711966
Ruthbelle520251976

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawisconsinwyoming

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