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

Green Heron Population Trend in Missouri

All statesWetland birds

Green Heron in Missouri has fallen sharply: down 50% on the route-weighted index since 1969.

-50%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 →
84Routes 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 MissouriNotable 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 declinecomputed 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 →

Green Heron has fallen sharply in Missouri: down 50% on the route-weighted index since 1969.

Green Heron Population Forecast in Missouri

If the recent trend holds, Green Heron in Missouri is projected to fall about 42% by 2029 — from 0.57 in 2024 to a central estimate of 0.33 (95% range 0.00–0.79). A 5-year backtest shows a typical error of ±46.2%, with 100% of held-out values landing inside the 95% band.

-42%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 →
0.33Projected 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 →
0.00–0.7995% 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 →
±46.2%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 Missouri is projected to fall about 42% by 2029 — from 0.57 in 2024 to a central estimate of 0.33 (95% range 0.00–0.79). A 5-year backtest shows a typical error of ±46.2%, 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 →
20250.380.000.84
20260.360.000.83
20270.350.000.81
20280.340.000.80
20290.330.000.79

Green Heron Survey Routes in Missouri

Routes recording Green Heron in Missouri.
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 →
Pulaski620151975
Rockingham419991971
Stet419901972
Sedalia420241991
Milford420242018
Sni Mills319901968
Sticklervill320121972
Trenton320011975
Kearney320241994
Gildehouse319891979
Auburn320242014
Mincy320242019
Cp Girardeau220231968
Cascade220241970
Ironton219801973
Wesco220231974
Clementine219961975
Cole Camp219891974
Rensselaer220071984
Bolckow219901967
Marshfield220171994
Osage Beach220241999
Graniteville220231982
Woodlandville220242013
Lincoln220192018

Green Heron Population Trend in Other States

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

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