BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Pied-billed Grebe In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionWetland birds

Pied-billed Grebe in Boreal Hardwood Transition has collapsed: down 82% on the route-weighted index since 1969.

-82%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 →
57Routes 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 →
56YearsYears 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 collapsed in Boreal Hardwood Transition: down 82% on the route-weighted index since 1969.

Pied-billed Grebe In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Pied-billed Grebe in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.08 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±299.8%, 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 →
0.08Projected 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 →
±299.8%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, Pied-billed Grebe in Boreal Hardwood Transition is projected to stay roughly flat through 2029, near 0.08 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±299.8%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.090.000.23
20260.090.000.23
20270.080.000.23
20280.080.000.23
20290.080.000.23

Routes In Boreal Hardwood Transition

Routes recording Pied-billed Grebe in Boreal 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 →
Bear LakeMICHIGAN111969
Seney NwrMICHIGAN42018
Pine RiverMICHIGAN32021
GreenbushMINNESOTA32016
BerglandMICHIGAN21993
ShingletonMICHIGAN21990
MuskallongeMICHIGAN22019
RiggsvilleMICHIGAN21985
Wigwam BayMINNESOTA22019
BackusMINNESOTA22022
LudeMINNESOTA22009
BrainerdMINNESOTA22011
BigforkMINNESOTA21998
Cass LakeMINNESOTA22016
MinongWISCONSIN21998
ExelandWISCONSIN22003
Rib LakeWISCONSIN22015
BootjackMICHIGAN11993
Ned LakeMICHIGAN12018
Crystal FlsMICHIGAN12017
Gibbs CityMICHIGAN11998
CreightonMICHIGAN12006
TahquamenonMICHIGAN12002
Lake CityMICHIGAN12006
IronsMICHIGAN11977

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