BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

American Bittern In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieWetland birds

American Bittern in Eastern Tallgrass Prairie has declined: down 28% on the route-weighted index since 1972.

-28%Since 1972TrendPercent 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 →
27Routes 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 →
30YearsYears 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 American Bittern in Eastern Tallgrass Prairie. See the full index history below.

American Bittern In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, American Bittern in Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±32.4%, 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 →
0.01Projected 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 →
0.00–0.0295% 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 →
±32.4%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 Eastern Tallgrass Prairie is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.02). A 5-year backtest shows a typical error of ±32.4%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.010.000.02
20260.010.000.02
20270.010.000.02
20280.010.000.02
20290.010.000.02

Routes In Eastern Tallgrass Prairie

Routes recording American Bittern in Eastern Tallgrass Prairie.
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 →
Trading PostKANSAS32012
BartonvilleILLINOIS22019
JamestownILLINOIS21979
Lake SummersetILLINOIS22012
OhioMISSOURI22004
HuntsvilleMISSOURI21984
GeneseoILLINOIS11975
New LenoxILLINOIS11976
ChandlervillILLINOIS11978
Terre HauteILLINOIS12001
ClarksdaleILLINOIS11971
DudleyvilleILLINOIS12005
HebronINDIANA11976
WabashINDIANA11987
Portage 2INDIANA12017
Kankakee SandsINDIANA12024
DinsdaleIOWA11985
BarclayKANSAS12008
OlsburgKANSAS12016
Ash CreekMINNESOTA11991
LakevilleMINNESOTA11974
RockinghamMISSOURI11974
StetMISSOURI11992
GretnaNEBRASKA11972
IrvingtonNEBRASKA11970

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