BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Black-crowned Night Heron In Coastal California

All regionsCoastal CaliforniaWetland birds

Black-crowned Night Heron in Coastal California has surged: up 119% on the route-weighted index since 1971.

+119%Since 1971
52Routes In Region
55Years

Notable Signals

long arc increasecomputed index

Black-crowned Night Heron has surged in Coastal California: up 119% on the route-weighted index since 1971.

Forecast

If the recent trend holds, Black-crowned Night Heron in Coastal California is projected to rise about 48% by 2029 — from 0.30 in 2024 to a central estimate of 0.44 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±885.9%, with 100% of held-out values landing inside the 95% band.

+48%Change by 2029
0.44Projected 2029 index
0.00–1.695% range
±885.9%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20250.470.001.7
20260.460.001.7
20270.460.001.6
20280.450.001.6
20290.440.001.6

Routes In Coastal California

Routes recording Black-crowned Night Heron in Coastal California.
Ora LomaCALIFORNIA281983
OrlandCALIFORNIA92014
Buena VistaCALIFORNIA62019
BakersfieldCALIFORNIA52023
MorenoCALIFORNIA52024
Harbor LakeCALIFORNIA41991
Foster ParkCALIFORNIA31993
AtwaterCALIFORNIA32007
Red BluffCALIFORNIA21992
CollegevilleCALIFORNIA21975
Orange CoveCALIFORNIA22004
CohassetCALIFORNIA21985
PowayCALIFORNIA21980
SisquocCALIFORNIA21994
Cp. PendletonCALIFORNIA21993
ArvinCALIFORNIA22016
OrovilleCALIFORNIA22024
MoragaCALIFORNIA22004
Mark WestCALIFORNIA22024
CoyoteCALIFORNIA22024
OnealsCALIFORNIA21983
Glen EllenCALIFORNIA21996
PenningtonCALIFORNIA11995
RumseyCALIFORNIA11990
ColmaCALIFORNIA11968

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