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

Green Heron Population Trend in Louisiana

All statesWetland birds

Green Heron in Louisiana has declined: down 39% on the route-weighted index since 1969.

-39%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 →
98Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Green Heron 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 Green Heron in Louisiana. See the full index history below.

Green Heron Population Forecast in Louisiana

If the recent trend holds, Green Heron in Louisiana is projected to fall about 12% by 2029 — from 1.7 in 2024 to a central estimate of 1.5 (95% range 0.07–2.9). A 5-year backtest shows a typical error of ±41.6%, with 100% of held-out values landing inside the 95% band.

-12%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 →
1.5Projected 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 →
0.07–2.995% 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 →
±41.6%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, Green Heron in Louisiana is projected to fall about 12% by 2029 — from 1.7 in 2024 to a central estimate of 1.5 (95% range 0.07–2.9). A 5-year backtest shows a typical error of ±41.6%, 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 →
20251.60.173.0
20261.50.142.9
20271.50.122.9
20281.50.102.9
20291.50.072.9

Green Heron Survey Routes in Louisiana

Routes recording Green Heron 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 →
Junior1719911987
Gran Chenier1719821970
Ltl Chenier 21320112010
Forked Island1320242008
Gibson1220191999
Esther1020241988
Forked Island 21020112010
Sabine Nwr 2920172009
Creole819871967
Mamou819821967
Shaw720241967
Ltl Chenier720241986
Baton Rouge720241995
Cypress619871967
Sabine Nwr620081989
Goodwill620212006
Grand Isle520192010
Easton419901967
Hackberry420161967
Berwick420181987
Rayville 2420242009
River Road420231987
Lafitte319911967
Larose319921988
Greensburg320221988

Green Heron Population Trend in Other States

alabamaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsin

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