BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

Black-crowned Night Heron In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

Black-crowned Night Heron in Prairie Hardwood Transition has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
46Routes 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 →
51YearsYears 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 fallen sharply in Prairie Hardwood Transition: down 61% on the route-weighted index since 1968.

Black-crowned Night Heron In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Black-crowned Night Heron in Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±119.6%, 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 →
0.00Projected 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 →
0.00–0.1295% 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 →
±119.6%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 Prairie Hardwood Transition is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±119.6%, 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 →
20250.010.000.13
20260.010.000.13
20270.010.000.13
20280.000.000.13
20290.000.000.12

Routes In Prairie Hardwood Transition

Routes recording Black-crowned Night Heron in Prairie Hardwood Transition.
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 →
Indiana DuneINDIANA52009
BrownsvilleWISCONSIN51990
BismarkOHIO41995
PrincetonWISCONSIN41993
Pt WashingtnWISCONSIN42015
Omro 2WISCONSIN42009
CoopersvilleMICHIGAN31985
GraytownOHIO31984
DresserWISCONSIN31978
ManitowocWISCONSIN32024
Rolling PrWISCONSIN32013
Columbia CtyINDIANA22023
HungerfordMICHIGAN22016
New BuffaloMICHIGAN21996
Money CreekMINNESOTA21999
OsseoMINNESOTA21991
KnappMINNESOTA21984
Le CenterMINNESOTA21999
CascoWISCONSIN21994
Fall RiverWISCONSIN21969
GuilfordILLINOIS11981
EllisINDIANA11986
Big Blue LkMICHIGAN11985
BravoMICHIGAN12015
St CharlesMICHIGAN11995

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