BirdAnalyst
Species · BCR 29 · BBS 2025 Release · 1966–2024

Yellow Warbler In Piedmont

All regionsPiedmontForest birds

Yellow Warbler in Piedmont has fallen sharply: down 52% on the route-weighted index since 1968.

-52%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 →
100Routes 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 →

Yellow Warbler has fallen sharply in Piedmont: down 52% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Yellow Warbler in Piedmont is projected to rise about 143% by 2029 — from 0.37 in 2024 to a central estimate of 0.89 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±240.6%, with 60% of held-out values landing inside the 95% band.

+143%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 →
0.89Projected 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 →
0.00–1.895% 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 →
±240.6%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, Yellow Warbler in Piedmont is projected to rise about 143% by 2029 — from 0.37 in 2024 to a central estimate of 0.89 (95% range 0.00–1.8). A 5-year backtest shows a typical error of ±240.6%, with 60% 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 →
20250.930.001.9
20260.920.001.9
20270.910.001.9
20280.900.001.8
20290.890.001.8

Routes In Piedmont

Routes recording Yellow 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 →
West GrovePENNSYLVANIA351996
CrotonNEW-JERSEY132007
GilletteNEW-JERSEY62024
CherryvilleNORTH-CAROLINA51968
CopelandNORTH-CAROLINA51975
EarltonMARYLAND42024
MooresvilleNORTH-CAROLINA42001
Mt GretnaPENNSYLVANIA42000
EmmitsburgMARYLAND32024
Pleasant ValMARYLAND32024
EkloMARYLAND32018
RandallstownMARYLAND32013
Bald FriarMARYLAND31996
Croton 2NEW-JERSEY32023
PottstownPENNSYLVANIA31987
Brick TavernPENNSYLVANIA32024
BendersvillePENNSYLVANIA32023
ChathamPENNSYLVANIA32024
TaylorstownVIRGINIA32007
IrisburgVIRGINIA32012
MillervilleALABAMA21973
LanettALABAMA21982
CrestGEORGIA21993
MaxeysGEORGIA21990
BaldwinGEORGIA22005

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