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Species · Oregon · BBS 2025 Release · 1966–2024

Black-crowned Night Heron Population Trend in Oregon

All statesWetland birds

Black-crowned Night Heron in Oregon has collapsed: down 87% on the route-weighted index since 1973.

-87%Since 1973TrendPercent 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 →
20Routes In StateSurvey 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 Black-crowned Night Heron Trends in OregonNotable 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 Oregon: down 87% on the route-weighted index since 1973.

Black-crowned Night Heron Population Forecast in Oregon

If the recent trend holds, Black-crowned Night Heron in Oregon is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±26.8%, 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 →
0.00–0.2095% 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 →
±26.8%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 Oregon is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±26.8%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.020.000.21
20260.010.000.21
20270.010.000.20
20280.010.000.20
20290.000.000.20

Black-crowned Night Heron Survey Routes in Oregon

Routes recording Black-crowned Night Heron in Oregon.
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 →
Fish Lake320181972
Barnes Val219721972
Princeton219851972
Coquille219971997
Umatilla220211989
Lapham Res.120021993
Days Creek119711971
Malheur Nwr119981986
Modoc Point120181971
Sparta119921992
Pendleton119961996
Adrian119951989
Hazel Camp120141996
Blizzard Gap120231987
Merrill119931993
Warner Vally120091993
Catlow Rim120241996
Sheaville120242012
Chinchalo120111993
Trout Creek120001998

Black-crowned Night Heron Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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