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Species · Louisiana · BBS 2025 Release · 1966–2024

Common Gallinule Population Trend in Louisiana

All statesWetland birds

Common Gallinule in Louisiana has surged: up 378% on the route-weighted index since 1971.

+378%Since 1971TrendPercent 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 →
36Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common 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 →

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 →

Common Gallinule has surged in Louisiana: up 378% on the route-weighted index since 1971.

Common Gallinule Population Forecast in Louisiana

If the recent trend holds, Common Gallinule in Louisiana is projected to fall about 34% by 2029 — from 2.9 in 2024 to a central estimate of 1.9 (95% range 0.00–4.8). A 5-year backtest shows a typical error of ±100.4%, with 100% of held-out values landing inside the 95% band.

-34%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 →
1.9Projected 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 →
0.00–4.895% 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 →
±100.4%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, Common Gallinule in Louisiana is projected to fall about 34% by 2029 — from 2.9 in 2024 to a central estimate of 1.9 (95% range 0.00–4.8). A 5-year backtest shows a typical error of ±100.4%, 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 →
20251.80.004.8
20261.90.004.8
20271.90.004.8
20281.90.004.8
20291.90.004.8

Common Gallinule Survey Routes in Louisiana

Routes recording Common 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 →
Ltl Chenier6120241986
Forked Island4520242008
Forked Island 22320102010
Mamou1519791978
Ltl Chenier 21320102010
Port Allen820132006
Sabine Nwr 2720172012
Maurice620241988
Ville Platte619961991
Woodlawn420212008
Hackberry320111971
Esther320241989
Lafitte219881988
Gran Chenier219821970
Mayflower220222022
Vinton 2220172014
Ramah220231994
Hackberry 2220212018
Carlisle119881988
Creole119871967
Atchafalaya120091994
Baton Rouge120212021
Keystone120091979
Shaw120242008
Derry119671967

Common Gallinule Population Trend in Other States

alabamaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippinevadanew-jerseynew-yorknorth-carolinaohiopennsylvaniasouth-carolinatennesseetexasutahvermontwisconsin

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