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Species · Kansas · BBS 2025 Release · 1966–2024

American Bittern Population Trend in Kansas

All statesWetland birds

American Bittern in Kansas has surged: up 78% on the route-weighted index since 1977.

+78%Since 1977TrendPercent 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 →
7Routes 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 →
29YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Bittern 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 increasecomputed 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 →

American Bittern has surged in Kansas: up 78% on the route-weighted index since 1977.

American Bittern Population Forecast in Kansas

If the recent trend holds, American Bittern in Kansas is projected to fall about 34% by 2024 — from 0.09 in 2019 to a central estimate of 0.06 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±46.8%, with 100% of held-out values landing inside the 95% band.

-34%Change by 2024TrendPercent 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 →
0.06Projected 2024 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 →
±46.8%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, American Bittern in Kansas is projected to fall about 34% by 2024 — from 0.09 in 2019 to a central estimate of 0.06 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±46.8%, with 100% of held-out values landing inside the 95% band.19692024
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 →
20200.060.000.12
20210.060.000.12
20220.060.000.12
20230.060.000.12
20240.060.000.12

American Bittern Survey Routes in Kansas

Routes recording American Bittern 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 →
Albert420191969
Trading Post320122009
Gray319941987
Coats119791979
Barclay120082008
Buckeye119741974
Olsburg120162016

American Bittern Population Trend in Other States

alaskacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowalouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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