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Species · Louisiana · BBS 2026 Release · 1966–2025

Purple Martin Population Trend in Louisiana

All statesAerial insectivores

Purple Martin in Louisiana has edged down: down 21% on the route-weighted index since 1969.

-21%Since 1969TrendPercent 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 →
100Routes 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 LouisianaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Purple Martin in Louisiana. See the full index history below.

Purple Martin Population Forecast in Louisiana

If the recent trend holds, Purple Martin in Louisiana is projected to stay roughly flat through 2030, near 17 (95% range 2.6–30). A 5-year backtest shows a typical error of ±52.4%, with 80% of held-out values landing inside the 95% band.

+2%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 →
17Projected 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 →
2.6–3095% 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 →
±52.4%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 Louisiana is projected to stay roughly flat through 2030, near 17 (95% range 2.6–30). A 5-year backtest shows a typical error of ±52.4%, with 80% of held-out values landing inside the 95% band.19672030
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 →
2026173.531
2027173.331
2028173.131
2029172.931
2030172.630

Purple Martin Survey Routes in Louisiana

Routes recording Purple Martin in Louisiana.
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 →
Carlisle19519881968
Cypress13719871967
Morgan City12519861967
Natchitoches10819911987
Forked Island 29420112010
Ltl Chenier 28320112010
Larose6919921988
Marion6219961988
Hackberry 26020252018
Easton5919901967
Many5619921989
River Road5520251987
Keystone4920131967
Linville4820251998
Junior4719911987
Longstreet4420251967
Lafitte4219911967
Brousville4220251998
Ivan 23920252014
Carterville3719921992
Gibson3720191999
Clay3420251968
Berwick3420181987
Glencoe3320181988
Woodlawn3220212008

Purple Martin Population Trend in Other States

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

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