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

Little Blue Heron Population Trend in Tennessee

All statesWetland birds

Little Blue Heron in Tennessee has surged: up 196% on the route-weighted index since 1970.

+196%Since 1970TrendPercent 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 →
10Routes 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 →
33YearsYears 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 TennesseeNotable 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 →

Little Blue Heron has surged in Tennessee: up 196% on the route-weighted index since 1970.

Little Blue Heron Population Forecast in Tennessee

If the recent trend holds, Little Blue Heron in Tennessee is projected to stay roughly flat through 2020, near 0.28 (95% range 0.00–0.73). A 5-year backtest shows a typical error of ±503.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2020TrendPercent 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 →
0.28Projected 2020 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7395% 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 →
±503.4%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, Little Blue Heron in Tennessee is projected to stay roughly flat through 2020, near 0.28 (95% range 0.00–0.73). A 5-year backtest shows a typical error of ±503.4%, with 100% of held-out values landing inside the 95% band.19662020
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 →
20160.280.000.72
20170.280.000.72
20180.280.000.73
20190.280.000.73
20200.280.000.73

Little Blue Heron Survey Routes in Tennessee

Routes recording Little Blue Heron in Tennessee.
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 →
Tiptonville1419941966
Whiteville320001966
Pawpaw220041969
Moscow119851972
Brownsville120032002
Tibbs119971979
Trenton119761976
Humboldt120002000
Collinwood119831982
Glen120152011

Little Blue Heron Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoiskansaskentuckylouisianamarylandmassachusettsmississippimissourinew-jerseynew-yorknorth-carolinanorth-dakotaoklahomapennsylvaniarhode-islandsouth-carolinatexasvirginia

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