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

Purple Martin Population Trend in West Virginia

All statesAerial insectivores

Purple Martin in West Virginia has fallen sharply: down 66% on the route-weighted index since 1968.

-66%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 →
37Routes 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 Purple Martin 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 →

Purple Martin has fallen sharply in West Virginia: down 66% on the route-weighted index since 1968.

Purple Martin Population Forecast in West Virginia

If the recent trend holds, Purple Martin in West Virginia is projected to rise about 41% by 2029 — from 0.35 in 2024 to a central estimate of 0.50 (95% range 0.00–2.0). A 5-year backtest shows a typical error of ±51.3%, with 100% of held-out values landing inside the 95% band.

+41%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 →
0.50Projected 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 →
0.00–2.095% 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 →
±51.3%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, Purple Martin in West Virginia is projected to rise about 41% by 2029 — from 0.35 in 2024 to a central estimate of 0.50 (95% range 0.00–2.0). A 5-year backtest shows a typical error of ±51.3%, 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 →
20250.580.002.1
20260.560.002.1
20270.540.002.0
20280.520.002.0
20290.500.002.0

Purple Martin Survey Routes in West Virginia

Routes recording Purple Martin 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 →
Paradise1320231967
Martinsburg1220131969
Welch820221980
Pt Pleasant720232006
Olcott720191967
Shanghai720221995
Hubbardstown619911972
Slate620231992
Rockport520241966
Josephs Mill520232017
Greer519721969
Clendenin420172017
Sugar Grove420231976
Dailey419911986
Sleepy Creek419881968
Stollings320172017
Clear Creek320242019
Meadland320242005
Sutton320232012
Clinton320181967
Hanover220241980
Breeden219861986
Arlee219751969
Yawkey220231966
Meadowville220181992

Purple Martin Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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