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Species · Tennessee · BBS 2025 Release · 1966–2024

Yellow-crowned Night Heron Population Trend in Tennessee

All statesWetland birds

Yellow-crowned Night Heron in Tennessee has declined: down 34% on the route-weighted index since 1973.

-34%Since 1973TrendPercent 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 →
15Routes 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 →
24YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-crowned Night 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 →

No notable trend signals for Yellow-crowned Night Heron in Tennessee. See the full index history below.

Yellow-crowned Night Heron Population Forecast in Tennessee

If the recent trend holds, Yellow-crowned Night Heron in Tennessee is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±52.6%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.01Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1295% 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 →
±52.6%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, Yellow-crowned Night Heron in Tennessee is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±52.6%, with 100% of held-out values landing inside the 95% band.19672027
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 →
20230.020.000.13
20240.020.000.13
20250.010.000.12
20260.010.000.12
20270.010.000.12

Yellow-crowned Night Heron Survey Routes in Tennessee

Routes recording Yellow-crowned Night 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 →
Moscow519871985
Humboldt519861973
Collinwood219751975
Tiptonville120121972
Pawpaw120121982
Lovell120082008
Oliver Spgs119931993
Whiteville120221974
Mansfield120041974
Allens Brdge119801967
Silerton119791979
Trenton119761976
Belotes Bend120012001
Red Bank119771977
Soddy119781972

Yellow-crowned Night Heron Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamarylandmississippimissourinew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniasouth-carolinatexasvirginiawest-virginia

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