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

Swainson's Warbler In Piedmont

All regionsPiedmontForest birds

Swainson's Warbler in Piedmont has surged: up 565% on the route-weighted index since 1981.

+565%Since 1981TrendPercent 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 →
32Routes 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 Swainson's Warbler in Piedmont. See the full index history below.

Swainson's Warbler In Piedmont Population Forecast

If the recent trend holds, Swainson's Warbler in Piedmont is projected to fall about 40% by 2030 — from 0.16 in 2025 to a central estimate of 0.10 (95% range 0.03–0.17). A 5-year backtest shows a typical error of ±60.1%, with 0% of held-out values landing inside the 95% band.

-40%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 →
0.10Projected 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 →
0.03–0.1795% 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 →
±60.1%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, Swainson's Warbler in Piedmont is projected to fall about 40% by 2030 — from 0.16 in 2025 to a central estimate of 0.10 (95% range 0.03–0.17). A 5-year backtest shows a typical error of ±60.1%, with 0% of held-out values landing inside the 95% band.19792030
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 →
20260.090.020.16
20270.090.030.16
20280.090.030.16
20290.100.030.16
20300.100.030.17

Routes In Piedmont

Routes recording Swainson's Warbler 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 →
MillervilleALABAMA42025
Liberty City 2ALABAMA32025
BowdonGEORGIA32025
Yates CrossroadsGEORGIA22023
OakboroNORTH-CAROLINA22025
Plum BranchSOUTH-CAROLINA21988
LanettALABAMA12024
Liberty CityALABAMA12005
Nixburg 2ALABAMA12021
WedoweeALABAMA12023
ForsythGEORGIA12024
BaldwinGEORGIA11981
GrovetownGEORGIA12019
StockbridgeGEORGIA11985
RutledgeGEORGIA12024
JulietteGEORGIA12025
WhitesburgGEORGIA12015
Lincolnton 2GEORGIA12022
SharonGEORGIA12018
Sunny SideGEORGIA12019
Rock BranchGEORGIA12022
Stoney Point 2GEORGIA12022
Piedmont NwrGEORGIA11991
JordanNORTH-CAROLINA11979
ArcolaNORTH-CAROLINA12000

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