BirdAnalyst
Species · Kentucky · BBS 2026 Release · 1966–2025

Purple Martin Population Trend in Kentucky

All statesAerial insectivores

Purple Martin in Kentucky has surged: up 125% on the route-weighted index since 1968.

+125%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 Purple Martin Trends in KentuckyNotable 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 increasecomputed 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 surged in Kentucky: up 125% on the route-weighted index since 1968.

Purple Martin Population Forecast in Kentucky

If the recent trend holds, Purple Martin in Kentucky is projected to fall about 23% by 2030 — from 13 in 2025 to a central estimate of 9.7 (95% range 6.4–13). A 5-year backtest shows a typical error of ±29.3%, with 100% of held-out values landing inside the 95% band.

-23%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 →
9.7Projected 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 →
6.4–1395% 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 →
±29.3%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 Kentucky is projected to fall about 23% by 2030 — from 13 in 2025 to a central estimate of 9.7 (95% range 6.4–13). A 5-year backtest shows a typical error of ±29.3%, 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 →
20269.46.113
20279.56.213
20289.66.213
20299.66.313
20309.76.413

Purple Martin Survey Routes in Kentucky

Routes recording Purple Martin in Kentucky.
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 →
Sewell Shop3920251968
Keysburg3720251969
Plum2820251966
East Union2220251966
Drakesboro2120031966
Shiloh1920251969
Glencoe1920181966
Eastview1720251968
Cedar Grove1520251969
Johnsonville1520211967
Hustonville1420251966
Canton1320251967
Mcbrayer1320251966
Bays Fork1320191999
Hegira1220241988
Bardwell1020031970
Riverqueen1020252007
Pleasurevill1020251980
Lebanon Junction1020252000
Lovelacevile920251967
Brownsville820242023
Dixie820191971
Beattyville720011967
Million 2720232006
Sulphur Lick620241968

Purple Martin Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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