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

Pied-billed Grebe In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

Pied-billed Grebe in Prairie Hardwood Transition has fallen sharply: down 69% on the route-weighted index since 1968.

-69%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 →
70Routes 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 →
58YearsYears 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 →

Pied-billed Grebe has fallen sharply in Prairie Hardwood Transition: down 69% on the route-weighted index since 1968.

Pied-billed Grebe In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Pied-billed Grebe in Prairie Hardwood Transition is projected to fall about 17% by 2029 — from 0.11 in 2024 to a central estimate of 0.09 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±125.9%, with 100% of held-out values landing inside the 95% band.

-17%Change 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 →
0.09Projected 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 →
0.00–0.2395% 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 →
±125.9%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, Pied-billed Grebe in Prairie Hardwood Transition is projected to fall about 17% by 2029 — from 0.11 in 2024 to a central estimate of 0.09 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±125.9%, 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 →
20250.100.000.24
20260.100.000.24
20270.100.000.24
20280.090.000.23
20290.090.000.23

Routes In Prairie Hardwood Transition

Routes recording Pied-billed Grebe 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 →
HoltMICHIGAN71981
Fall RiverWISCONSIN72019
FestinaIOWA52005
Sherburne NrMINNESOTA52024
Columbia CtyINDIANA41998
HudsonWISCONSIN32016
LawrenceMICHIGAN22009
HowardsvilleMICHIGAN22009
Barry S.G.A.MICHIGAN22005
MinnetonkaMINNESOTA22021
PrincetonMINNESOTA22016
KnappMINNESOTA22024
Le CenterMINNESOTA22016
GlenwoodMINNESOTA22019
ClintonvilleWISCONSIN22024
PardeevilleWISCONSIN21994
PrincetonWISCONSIN22005
EdenWISCONSIN21973
KnoxINDIANA12012
PackertownINDIANA11973
EllisINDIANA11988
LagrangeINDIANA12011
Indiana DuneINDIANA12002
Big Blue LkMICHIGAN12024
NashvilleMICHIGAN11981

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