BirdAnalyst
Species · Kentucky · BBS 2025 Release · 1966–2024

Purple Martin Population Trend in Kentucky

All statesAerial insectivores

Purple Martin in Kentucky has risen sharply: up 73% on the route-weighted index since 1968.

+73%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 →
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 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 risen sharply in Kentucky: up 73% 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 rise about 27% by 2029 — from 7.4 in 2024 to a central estimate of 9.4 (95% range 6.1–13). A 5-year backtest shows a typical error of ±29.4%, with 100% of held-out values landing inside the 95% band.

+27%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 →
9.4Projected 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 →
6.1–1395% 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 →
±29.4%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 rise about 27% by 2029 — from 7.4 in 2024 to a central estimate of 9.4 (95% range 6.1–13). A 5-year backtest shows a typical error of ±29.4%, 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 →
20259.15.812
20269.25.912
20279.26.012
20289.36.113
20299.46.113

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 →
Keysburg3820241969
Drakesboro2120031966
Hustonville1920241966
Glencoe1920181966
Lebanon Junction1820242000
Shiloh1720231969
Kings Mtn1720241966
Mckee1620241967
Johnsonville1520211967
Bays Fork1320191999
Hegira1220241988
Plum1220241966
Bardwell1020031970
Sewell Shop1020231968
Brownsville820242023
Cedar Grove820241969
Mcbrayer820231966
Dixie820191971
Beattyville720011967
Morganfield720242022
Million 2720232006
Canton620241967
Sulphur Lick620241968
Riverqueen620242007
Hodgenville620011969

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 2026-05-22.