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Species · Kansas · BBS 2025 Release · 1966–2024

Black-crowned Night Heron Population Trend in Kansas

All statesWetland birds

Black-crowned Night Heron in Kansas has collapsed: down 90% on the route-weighted index since 1969.

-90%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 →
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 →
52YearsYears 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 KansasNotable 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 Kansas: down 90% on the route-weighted index since 1969.

Black-crowned Night Heron Population Forecast in Kansas

If the recent trend holds, Black-crowned Night Heron in Kansas is projected to fall about 100% by 2028 — from 0.18 in 2023 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±170.2%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2028TrendPercent 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 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–3.295% 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 →
±170.2%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 Kansas is projected to fall about 100% by 2028 — from 0.18 in 2023 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±170.2%, with 100% of held-out values landing inside the 95% band.19672028
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 →
20240.020.003.2
20250.000.003.2
20260.000.003.2
20270.000.003.2
20280.000.003.2

Black-crowned Night Heron Survey Routes in Kansas

Routes recording Black-crowned Night Heron in Kansas.
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 →
Grigston720082001
Leoti520032003
Albert320231967
Galesburg219851985
Wellington120231979
Dalton120171988
St John119991972
Coats119751974
Coldwater120041999
Olathe119901990
Ellinor120042004
Kanopolis119961996
Phillipsburg120072007
Gove119771977
Missler119941982
Berwet120062005
Plymell120232008
Olsburg120092007
Winona120162016
Solomon119961996

Black-crowned Night Heron Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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