BirdAnalyst
Species · West Virginia · BBS 2025 Release · 1966–2024

Chimney Swift Population Trend in West Virginia

All statesAerial insectivores

Chimney Swift in West Virginia has fallen sharply: down 71% on the route-weighted index since 1968.

-71%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 →
62Routes 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 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 71% 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 33% by 2029 — from 2.7 in 2024 to a central estimate of 1.8 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±32.7%, with 100% of held-out values landing inside the 95% band.

-33%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 →
1.8Projected 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 →
0.00–5.095% 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 →
±32.7%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 33% by 2029 — from 2.7 in 2024 to a central estimate of 1.8 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±32.7%, 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 →
20252.40.005.6
20262.20.005.4
20272.10.005.3
20282.00.005.1
20291.80.005.0

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
Clinton2020241966
Welch1520221980
Ruthbelle1520241976
Hix1320231970
Glade Run1320021989
Olcott1020241966
Paradise920231966
Three Forks920241971
Berryburg819961975
Josephs Mill820241993
Cedarville720231982
Glade Run 2720232003
Hubbardstown620221967
Richwood620231980
Smithfield620241993
Meadland520241997
Albright519711966
Bramwell420221978
Moundsville420241972
Rio419951974

Chimney Swift Population Trend in Other States

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

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