BirdAnalyst
Species · BCR 27 · BBS 2025 Release · 1966–2024

Black-crowned Night Heron In Southeastern Coastal Plain

All regionsSoutheastern Coastal PlainWetland birds

Black-crowned Night Heron in Southeastern Coastal Plain has collapsed: down 80% on the route-weighted index since 1968.

-80%Since 1968TrendPercent 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 →
68Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 collapsed in Southeastern Coastal Plain: down 80% on the route-weighted index since 1968.

Black-crowned Night Heron In Southeastern Coastal Plain Population Forecast

If the recent trend holds, Black-crowned Night Heron in Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±65.7%, 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 →
0.01Projected 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 →
0.00–0.1095% 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 →
±65.7%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 Southeastern Coastal Plain is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±65.7%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.010.000.10
20260.010.000.10
20270.010.000.10
20280.010.000.10
20290.010.000.10

Routes In Southeastern Coastal Plain

Routes recording Black-crowned Night Heron in Southeastern Coastal Plain.
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 →
DeepstepGEORGIA112001
DarienGEORGIA62019
Doctor InletFLORIDA51968
Harrietts BlGEORGIA32021
PlettenbergLOUISIANA31968
MerrimonNORTH-CAROLINA32013
HallsboroNORTH-CAROLINA32015
DaleSOUTH-CAROLINA32013
SealeALABAMA22001
MiccosukeeFLORIDA21978
Alligator PtFLORIDA22024
BostonGEORGIA21983
Ware CoGEORGIA22019
LakeMISSISSIPPI22006
SupplyNORTH-CAROLINA22021
ReelsboroNORTH-CAROLINA22013
Johns IsleSOUTH-CAROLINA21979
WaverlyVIRGINIA21986
St FlorianALABAMA11967
GreensboroALABAMA12015
WallsboroALABAMA12016
Warrior StdALABAMA11985
GrangeburgALABAMA11982
MclellanALABAMA11989
Dauphin IsALABAMA11976

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