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

Canada Warbler In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Canada Warbler in New England / Mid-Atlantic Coast has collapsed: down 90% on the route-weighted index since 1968.

-90%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 →
34Routes 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 →
56YearsYears 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 →

Canada Warbler has collapsed in New England / Mid-Atlantic Coast: down 90% on the route-weighted index since 1968.

Canada Warbler In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Canada Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±241.4%, 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 →
0.00Projected 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 →
0.00–0.0995% 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 →
±241.4%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, Canada Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±241.4%, 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 →
20250.000.000.09
20260.000.000.09
20270.000.000.09
20280.000.000.09
20290.000.000.09

Routes In New England / Mid-Atlantic Coast

Routes recording Canada 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 →
WarrenCONNECTICUT42011
BuckinghamCONNECTICUT31972
PrincetonMASSACHUSETTS21976
EpsomNEW-HAMPSHIRE22008
HuntingtonNEW-YORK21995
MysticCONNECTICUT11983
E HartlandCONNECTICUT11990
UncasvilleCONNECTICUT11977
WoodstockCONNECTICUT12004
WillimanticCONNECTICUT12000
No WoodburyCONNECTICUT11985
ShermanCONNECTICUT12008
DanburyCONNECTICUT11972
Long HillCONNECTICUT11982
Mid HaddamCONNECTICUT12014
GranbyCONNECTICUT12023
Kittery PtMAINE12019
MarionMASSACHUSETTS11992
NewburyportMASSACHUSETTS11968
BelchertownMASSACHUSETTS12024
WarrenMASSACHUSETTS11998
S BarreMASSACHUSETTS12005
HoldenMASSACHUSETTS11983
Ware RiverMASSACHUSETTS12022
BrentwoodNEW-HAMPSHIRE11990

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