BirdAnalyst
Species · BCR 23 · BBS 2025 Release · 1966–2024

American Bittern In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

American Bittern in Prairie Hardwood Transition has collapsed: down 79% on the route-weighted index since 1968.

-79%Since 1968TrendPercent 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 →
57YearsYears 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 →

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 →

American Bittern has collapsed in Prairie Hardwood Transition: down 79% on the route-weighted index since 1968.

American Bittern In Prairie Hardwood Transition Population Forecast

If the recent trend holds, American Bittern in Prairie Hardwood Transition 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 ±218.9%, 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 →
±218.9%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 Prairie Hardwood Transition 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 ±218.9%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.000.000.20
20260.000.000.20
20270.000.000.20
20280.000.000.20
20290.000.000.20

Routes In Prairie Hardwood Transition

Routes recording American Bittern in Prairie Hardwood Transition.
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 →
No BradleyMICHIGAN42015
HolwayWISCONSIN41983
PardeevilleWISCONSIN41999
MontereyMICHIGAN32023
ElderonWISCONSIN32016
BravoMICHIGAN22021
Drayton PlnsMICHIGAN21975
PrincetonMINNESOTA21990
Sherburne NrMINNESOTA22024
MatherWISCONSIN22023
Wis RapidsWISCONSIN22017
OmroWISCONSIN22000
Fall RiverWISCONSIN22004
Beaver DamWISCONSIN22004
BriggsvilleWISCONSIN22019
ScottvilleMICHIGAN11974
Big Blue LkMICHIGAN12021
New TroyMICHIGAN11985
NashvilleMICHIGAN12005
CoopersvilleMICHIGAN11987
BeldingMICHIGAN11990
GalesburgMICHIGAN11982
RemusMICHIGAN12004
St CharlesMICHIGAN11983
HoltMICHIGAN11978

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