BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Black-crowned Night Heron In Great Basin

All regionsGreat BasinWetland birds

Black-crowned Night Heron in Great Basin has surged: up 137% on the route-weighted index since 1971.

+137%Since 1971TrendPercent 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 →
76Routes 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 →
56YearsYears 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 →

No notable trend signals for Black-crowned Night Heron in Great Basin. See the full index history below.

Black-crowned Night Heron In Great Basin Population Forecast

If the recent trend holds, Black-crowned Night Heron in Great Basin is projected to rise about 72% by 2030 — from 0.12 in 2025 to a central estimate of 0.21 (95% range 0.00–0.61). A 5-year backtest shows a typical error of ±178.5%, with 100% of held-out values landing inside the 95% band.

+72%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 →
0.21Projected 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 →
0.00–0.6195% 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 →
±178.5%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 Great Basin is projected to rise about 72% by 2030 — from 0.12 in 2025 to a central estimate of 0.21 (95% range 0.00–0.61). A 5-year backtest shows a typical error of ±178.5%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.230.000.63
20270.230.000.63
20280.220.000.62
20290.210.000.61
20300.210.000.61

Routes In Great Basin

Routes recording Black-crowned Night Heron in Great Basin.
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 →
DorrisCALIFORNIA392019
Oak CityUTAH72011
BrewsterWASHINGTON71986
EurekaNEVADA61998
Catlow RimOREGON52025
FallonNEVADA42025
KeystoneWASHINGTON42022
PotholesWASHINGTON42019
Iron GateCALIFORNIA32017
TriangleIDAHO32021
MacdoelCALIFORNIA22018
Majors PlaceNEVADA22010
Ruby ValleyNEVADA21999
Barnes ValOREGON21972
PrincetonOREGON21985
Fish LakeOREGON22025
UmatillaOREGON22021
PrescottWASHINGTON22010
NubieberCALIFORNIA12016
RavendaleCALIFORNIA11995
LikelyCALIFORNIA12011
Crowley LakeCALIFORNIA12023
Honey LakeCALIFORNIA12025
Davis CreekCALIFORNIA12021
Clear Lk ResCALIFORNIA11999

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