BirdAnalyst
Species · BCR 29 · BBS 2026 Release · 1966–2025

Louisiana Waterthrush In Piedmont

All regionsPiedmontForest birds

Louisiana Waterthrush in Piedmont has surged: up 225% on the route-weighted index since 1968.

+225%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 →
122Routes 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 →
59YearsYears 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 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 →

Louisiana Waterthrush has surged in Piedmont: up 225% on the route-weighted index since 1968.

Louisiana Waterthrush In Piedmont Population Forecast

If the recent trend holds, Louisiana Waterthrush in Piedmont is projected to fall about 10% by 2030 — from 0.48 in 2025 to a central estimate of 0.43 (95% range 0.30–0.55). A 5-year backtest shows a typical error of ±9.7%, with 100% of held-out values landing inside the 95% band.

-10%Change by 2030TrendPercent 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 →
0.43Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.30–0.5595% 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 →
±9.7%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, Louisiana Waterthrush in Piedmont is projected to fall about 10% by 2030 — from 0.48 in 2025 to a central estimate of 0.43 (95% range 0.30–0.55). A 5-year backtest shows a typical error of ±9.7%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.410.280.54
20270.410.290.54
20280.420.290.55
20290.420.300.55
20300.430.300.55

Routes In Piedmont

Routes recording Louisiana Waterthrush in Piedmont.
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 →
EarltonMARYLAND42024
WashingtonGEORGIA32025
IjamsvilleMARYLAND32024
AmherstVIRGINIA32025
Big IslandVIRGINIA32025
CovesvilleVIRGINIA32025
MillervilleALABAMA22025
Liberty City 2ALABAMA22024
MaxeysGEORGIA22024
GrovetownGEORGIA22013
RutledgeGEORGIA22025
JulietteGEORGIA22025
WhitesburgGEORGIA22025
Lincolnton 2GEORGIA22025
Carrs StationGEORGIA22021
Rock BranchGEORGIA22025
Sharon 2GEORGIA22025
Silver SpgMARYLAND21988
DurhamNORTH-CAROLINA22024
Mount AiryNORTH-CAROLINA22018
PartlowVIRGINIA22000
ShipmanVIRGINIA22024
ElamsvilleVIRGINIA22016
AppomattoxVIRGINIA22016
Pw Forest PkVIRGINIA22009

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.