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Species · Louisiana · BBS 2025 Release · 1966–2024

Purple Gallinule Population Trend in Louisiana

All statesWetland birds

Purple Gallinule in Louisiana has increased: up 47% on the route-weighted index since 1970.

+47%Since 1970TrendPercent 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 →
20Routes 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 →
40YearsYears 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 Gallinule 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 Gallinule in Louisiana. See the full index history below.

Purple Gallinule Population Forecast in Louisiana

If the recent trend holds, Purple Gallinule in Louisiana is projected to fall about 52% by 2029 — from 0.29 in 2024 to a central estimate of 0.14 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±40.9%, with 100% of held-out values landing inside the 95% band.

-52%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 →
0.14Projected 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 →
0.00–0.4195% 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 →
±40.9%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, Purple Gallinule in Louisiana is projected to fall about 52% by 2029 — from 0.29 in 2024 to a central estimate of 0.14 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±40.9%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.140.000.41
20260.140.000.41
20270.140.000.41
20280.140.000.41
20290.140.000.41

Purple Gallinule Survey Routes in Louisiana

Routes recording Purple Gallinule 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 →
Forked Island820242008
Forked Island 2620102010
Mamou419801967
Ltl Chenier320241986
Morgan City220142013
Hackberry 2220182018
Gran Chenier119821980
Atchafalaya120151998
Easton119701970
Hackberry119981976
Shaw120222022
Glencoe119891989
Esther120242004
Ramah120222012
Maurice119951994
Kaplan120221998
Port Allen120132005
Richard119981998
Sabine Nwr 2120122012
Sabine Nwr120041989

Purple Gallinule Population Trend in Other States

alabamaarkansasfloridageorgiatexas

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