BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Black-crowned Night Heron In Badlands and Prairies

All regionsBadlands and PrairiesWetland birds

Black-crowned Night Heron in Badlands and Prairies has collapsed: down 78% on the route-weighted index since 1969.

-78%Since 1969TrendPercent 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 →
14Routes 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 →
22YearsYears 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 Badlands and Prairies: down 78% on the route-weighted index since 1969.

Black-crowned Night Heron In Badlands and Prairies Population Forecast

If the recent trend holds, Black-crowned Night Heron in Badlands and Prairies is projected to stay roughly flat through 2019, near 0.00 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±167.9%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2019TrendPercent 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 →
0.00Projected 2019 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0495% 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 →
±167.9%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 Badlands and Prairies is projected to stay roughly flat through 2019, near 0.00 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±167.9%, with 80% of held-out values landing inside the 95% band.19672019
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 →
20150.000.000.04
20160.000.000.04
20170.000.000.04
20180.000.000.04
20190.000.000.04

Routes In Badlands and Prairies

Routes recording Black-crowned Night Heron in Badlands and Prairies.
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 →
DwyerWYOMING21992
HighwoodMONTANA11993
RoyMONTANA11996
Two DotMONTANA11996
ShawmutMONTANA11996
Ft YatesNORTH-DAKOTA11989
Dunn CenterNORTH-DAKOTA11982
TobaccoNORTH-DAKOTA11979
BowmanNORTH-DAKOTA11986
BentleyNORTH-DAKOTA12013
ChamberlainSOUTH-DAKOTA11972
Ft ThompsonSOUTH-DAKOTA11998
OttumwaSOUTH-DAKOTA11967
LacreekSOUTH-DAKOTA12014

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