BirdAnalyst
Species · BCR 37 · BBS 2026 Release · 1966–2025

Black-crowned Night Heron In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Black-crowned Night Heron in Gulf Coastal Prairie has surged: up 147% on the route-weighted index since 1970.

+147%Since 1970TrendPercent 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 →
37Routes 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 →
55YearsYears 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 increasecomputed 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 surged in Gulf Coastal Prairie: up 147% on the route-weighted index since 1970.

Black-crowned Night Heron In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Black-crowned Night Heron in Gulf Coastal Prairie is projected to rise about 64% by 2030 — from 0.73 in 2025 to a central estimate of 1.2 (95% range 0.36–2.0). A 5-year backtest shows a typical error of ±69%, with 100% of held-out values landing inside the 95% band.

+64%Change by 2030TrendPercent 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 →
1.2Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.36–2.095% 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 →
±69%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 Gulf Coastal Prairie is projected to rise about 64% by 2030 — from 0.73 in 2025 to a central estimate of 1.2 (95% range 0.36–2.0). A 5-year backtest shows a typical error of ±69%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20261.10.312.0
20271.20.322.0
20281.20.332.0
20291.20.342.0
20301.20.362.0

Routes In Gulf Coastal Prairie

Routes recording Black-crowned Night Heron in Gulf Coastal Prairie.
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 →
WoodlawnLOUISIANA102021
Lag AtascosaTEXAS82023
ChinquapinTEXAS82025
CreoleLOUISIANA51987
Oyster LakeTEXAS52024
KaplanLOUISIANA42023
MauriceLOUISIANA32024
Ltl ChenierLOUISIANA32017
Forked IslandLOUISIANA32025
L. Atascosa NwrTEXAS32025
Gran ChenierLOUISIANA21982
RichardLOUISIANA22024
Grand IsleLOUISIANA22018
Ville PlatteLOUISIANA22019
Ltl Chenier 2LOUISIANA22011
Sabine Nwr 2LOUISIANA22017
StowellTEXAS22010
Rock IslandTEXAS22015
Goliad PrairieTEXAS22004
JuniorLOUISIANA11991
MamouLOUISIANA11982
HackberryLOUISIANA12013
EstherLOUISIANA12025
Sabine NwrLOUISIANA12002
Vinton 2LOUISIANA12022

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.