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

Bank Swallow Population Trend in West Virginia

All statesAerial insectivores

Bank Swallow in West Virginia has collapsed: down 97% on the route-weighted index since 1976.

-97%Since 1976TrendPercent 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 →
16Routes 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 →
22YearsYears 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 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 →

Bank Swallow has collapsed in West Virginia: down 97% on the route-weighted index since 1976.

Bank Swallow Population Forecast in West Virginia

If the recent trend holds, Bank Swallow in West Virginia is projected to stay roughly flat through 2009, near 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±2510.9%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2009TrendPercent 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 2009 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.795% 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 →
±2510.9%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 West Virginia is projected to stay roughly flat through 2009, near 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±2510.9%, with 100% of held-out values landing inside the 95% band.19672009
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 →
20050.000.001.7
20060.000.001.7
20070.000.001.7
20080.000.001.7
20090.000.001.7

Bank Swallow Survey Routes in West Virginia

Routes recording Bank Swallow 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 →
Green Bank1719971997
Hix1019821982
Sleepy Creek1019801967
Martinsburg819951967
Clear Creek619951995
Meadowville519841984
Clinton420001967
Three Forks319941994
Cedarville319871987
Hubbardstown219901981
Dailey119921992
Slate120021989
Washburn119861983
Welch120042004
Berryburg119781978
Valley Head119831983

Bank Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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