BirdAnalyst
Species · BCR 30 · BBS 2025 Release · 1966–2024

Nashville Warbler In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Nashville Warbler in New England / Mid-Atlantic Coast has fallen sharply: down 75% on the route-weighted index since 1968.

-75%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 →
26Routes 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 →
38YearsYears 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 fallen sharply in New England / Mid-Atlantic Coast: down 75% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Nashville Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2024, near 0.00 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±159.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2024TrendPercent 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 →
0.00Projected 2024 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1195% 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 →
±159.8%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, Nashville Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2024, near 0.00 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±159.8%, with 100% of held-out values landing inside the 95% band.19662024
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 →
20200.000.000.11
20210.000.000.11
20220.000.000.11
20230.000.000.11
20240.000.000.11

Routes In New England / Mid-Atlantic Coast

Routes recording Nashville Warbler in New England / Mid-Atlantic Coast.
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 →
Long HillCONNECTICUT21974
NewburyportMASSACHUSETTS21967
N OxfordMASSACHUSETTS21971
E PepperellMASSACHUSETTS21979
WoodstockCONNECTICUT12004
No WoodburyCONNECTICUT11982
DanburyCONNECTICUT11977
WarrenCONNECTICUT11978
SouthingtonCONNECTICUT11984
Cape NeddickMAINE11993
Kittery PtMAINE11992
MarionMASSACHUSETTS11971
WellfleetMASSACHUSETTS11986
PrattvilleMASSACHUSETTS12007
MaynardMASSACHUSETTS11972
PrincetonMASSACHUSETTS11974
BelchertownMASSACHUSETTS12019
WarrenMASSACHUSETTS11990
S BarreMASSACHUSETTS11981
HoldenMASSACHUSETTS11992
Ware RiverMASSACHUSETTS11993
BrentwoodNEW-HAMPSHIRE11993
DoverNEW-HAMPSHIRE11996
EpsomNEW-HAMPSHIRE11999
StraffordNEW-HAMPSHIRE12013

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