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

Little Blue Heron Population Trend in Missouri

All statesWetland birds

Little Blue Heron in Missouri has collapsed: down 99% on the route-weighted index since 1969.

-99%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 →
11Routes 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 →
41YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Little Blue 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 →

Little Blue Heron has collapsed in Missouri: down 99% on the route-weighted index since 1969.

Little Blue Heron Population Forecast in Missouri

If the recent trend holds, Little Blue Heron in Missouri is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±2618.2%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–2.295% 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 →
±2618.2%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, Little Blue Heron in Missouri is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–2.2). A 5-year backtest shows a typical error of ±2618.2%, 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 →
20250.000.002.2
20260.000.002.2
20270.000.002.2
20280.000.002.2
20290.000.002.2

Little Blue Heron Survey Routes in Missouri

Routes recording Little Blue 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 →
Rockingham819961990
Cp Girardeau320241967
Pineville220031987
Reeds220081996
Gildehouse219861986
Blodgett220192014
Deventer120131967
Norborne120162016
Hayden119901990
Whitewater120072006
Richland120162016

Little Blue Heron Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoiskansaskentuckylouisianamarylandmassachusettsmississippinew-jerseynew-yorknorth-carolinanorth-dakotaoklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginia

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