Black-crowned Night Heron Population Analysis
Black-crowned Night Heron has fallen sharply: down 58% on the route-weighted index since 1968.
About the Black-crowned Night Heron
The Black-crowned Night Heron (Nycticorax nycticorax) is a North American member of the Herons, Egrets & Bitterns (Ardeidae). In this analysis it is grouped with the wetland birds.
- Size
- 12–51 in long (30–130 cm) — a long-legged wader (typical for the family)
- Habitat
- Marshes, ponds, lakeshores and other freshwater wetlands.
- Diet
- Aquatic invertebrates, small fish, frogs and plant matter.
- Range
- Recorded on 819 Breeding Bird Survey routes across 48 states, most concentrated in the Great Basin.
- Family
- Ardeidae · Wetland birds
Notable Black-crowned Night Heron TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →
Black-crowned Night Heron has fallen sharply in surveyed states: down 58% on the route-weighted index since 1968.
Black-crowned Night Heron Population Forecast
If the recent trend holds, Black-crowned Night Heron is projected to rise about 52% by 2030 — from 0.05 in 2025 to a central estimate of 0.08 (95% range 0.00–0.16). A 5-year backtest shows a typical error of ±84.2%, with 100% of held-out values landing inside the 95% band.
Where the Black-crowned Night Heron Is Detected
BBS routes recording Black-crowned Night Heron, sized by most recent count.
Black-crowned Night Heron Population Trend by State
Black-crowned Night Heron Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
Black-crowned Night Heron Conservation Status
Our route-weighted index shows it down about 58% since 1968.
Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.