BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Nashville Warbler In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Nashville Warbler in Appalachian Mountains has collapsed: down 88% on the route-weighted index since 1968.

-88%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 →
64Routes 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 →
57YearsYears 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 →

Nashville Warbler has collapsed in Appalachian Mountains: down 88% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Nashville Warbler in Appalachian Mountains is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±64.5%, 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 →
0.01Projected 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 →
0.00–0.0495% 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 →
±64.5%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, Nashville Warbler in Appalachian Mountains is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±64.5%, 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 →
20250.010.000.05
20260.010.000.04
20270.010.000.04
20280.010.000.04
20290.010.000.04

Routes In Appalachian Mountains

Routes recording Nashville Warbler in Appalachian Mountains.
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 →
Platte CoveNEW-YORK22016
CoventryvileNEW-YORK22016
SwainNEW-YORK22003
ArnotPENNSYLVANIA21996
BemisWEST-VIRGINIA22002
AccidentMARYLAND11995
High PointNEW-JERSEY11998
CooperstownNEW-YORK11974
MeridaleNEW-YORK12023
S BerneNEW-YORK12008
LaurensNEW-YORK12012
McdonoughNEW-YORK12015
CorbettsvileNEW-YORK11987
OneontaNEW-YORK11981
OxfordNEW-YORK11974
E NewarkNEW-YORK12015
DrydenNEW-YORK11999
Vestal CtrNEW-YORK11980
Phillips CrNEW-YORK12017
GainesvilleNEW-YORK11989
CentervilleNEW-YORK11971
S VandaliaNEW-YORK11966
DownsvilleNEW-YORK11990
MilfordNEW-YORK12014
Oxford 2NEW-YORK12007

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