BirdAnalyst
Species · North Carolina · BBS 2025 Release · 1966–2024

Black-crowned Night Heron Population Trend in North Carolina

All statesWetland birds

Black-crowned Night Heron in North Carolina has fallen sharply: down 51% on the route-weighted index since 1984.

-51%Since 1984TrendPercent 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 →
28YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-crowned Night Heron Trends in North CarolinaNotable 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 →

Black-crowned Night Heron has fallen sharply in North Carolina: down 51% on the route-weighted index since 1984.

Black-crowned Night Heron Population Forecast in North Carolina

If the recent trend holds, Black-crowned Night Heron in North Carolina is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±50.3%, 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 →
0.02Projected 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 →
0.00–0.0695% 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 →
±50.3%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, Black-crowned Night Heron in North Carolina is projected to stay roughly flat through 2027, near 0.02 (95% range 0.00–0.06). A 5-year backtest shows a typical error of ±50.3%, with 100% of held-out values landing inside the 95% band.19722027
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 →
20230.020.000.06
20240.020.000.06
20250.020.000.06
20260.020.000.06
20270.020.000.06

Black-crowned Night Heron Survey Routes in North Carolina

Routes recording Black-crowned Night Heron in North Carolina.
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 →
Merrimon320131972
Hallsboro320152015
Fairview220082008
Supply220211993
Reelsboro220132013
Shallotte119861984
Myrtle Grove120221975
Jarvisburg 2120122010
Milltail Cr120221994
Maple Hill120212021

Black-crowned Night Heron Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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