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

Great Blue Heron Population Trend in Louisiana

All statesWetland birds

Great Blue Heron in Louisiana has surged: up 101% on the route-weighted index since 1969.

+101%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 →
94Routes 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 Great Blue 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 →

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 →

Great Blue Heron has surged in Louisiana: up 101% on the route-weighted index since 1969.

Great Blue Heron Population Forecast in Louisiana

If the recent trend holds, Great Blue Heron in Louisiana is projected to rise about 107% by 2029 — from 1.0 in 2024 to a central estimate of 2.1 (95% range 0.30–3.8). A 5-year backtest shows a typical error of ±169.1%, with 80% of held-out values landing inside the 95% band.

+107%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 →
2.1Projected 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 →
0.30–3.895% 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 →
±169.1%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, Great Blue Heron in Louisiana is projected to rise about 107% by 2029 — from 1.0 in 2024 to a central estimate of 2.1 (95% range 0.30–3.8). A 5-year backtest shows a typical error of ±169.1%, with 80% 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 →
20252.00.283.8
20262.10.283.8
20272.10.293.8
20282.10.293.8
20292.10.303.8

Great Blue Heron Survey Routes in Louisiana

Routes recording Great Blue 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 →
Gran Chenier1519821967
Natchitoches1319911987
Cypress819871974
Maurice820241989
Kraemer720231997
Ville Platte720191988
Ltl Chenier 2720112010
Freetown620091978
Morgan City619861967
Richard620242010
Woodlawn620212008
Atchafalaya620191989
Hackberry420161968
Rayville420071969
Grand Isle420192010
Morgan City420222011
River Road420211987
Belair320241991
Berwick320181987
Sabine Nwr 2320172009
Forked Island320242008
Baton Rouge320241995
Vinton 2320242011
Forked Island 2320112010
Lafitte219911967

Great Blue Heron Population Trend in Other States

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

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