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

Blackburnian Warbler In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Blackburnian Warbler in New England / Mid-Atlantic Coast has risen sharply: up 61% on the route-weighted index since 1969.

+61%Since 1969TrendPercent 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 →
27Routes 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 →
55YearsYears 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 increasecomputed 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 →

Blackburnian Warbler has risen sharply in New England / Mid-Atlantic Coast: up 61% on the route-weighted index since 1969.

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

If the recent trend holds, Blackburnian Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±45.8%, with 100% of held-out values landing inside the 95% band.

-2%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 →
0.05Projected 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 →
0.00–0.1295% 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 →
±45.8%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, Blackburnian Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±45.8%, 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 →
20250.050.000.13
20260.050.000.12
20270.050.000.12
20280.050.000.12
20290.050.000.12

Routes In New England / Mid-Atlantic Coast

Routes recording Blackburnian 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
GranbyCONNECTICUT32023
WoodstockCONNECTICUT21995
Long HillCONNECTICUT22019
PrincetonMASSACHUSETTS21976
BelchertownMASSACHUSETTS22024
WarrenMASSACHUSETTS21984
HoldenMASSACHUSETTS21989
EpsomNEW-HAMPSHIRE22018
E HartlandCONNECTICUT11985
WillimanticCONNECTICUT12007
No WoodburyCONNECTICUT11977
DanburyCONNECTICUT11972
Woodstock 2CONNECTICUT12018
Warren 2CONNECTICUT12024
MarionMASSACHUSETTS11993
LittletonMASSACHUSETTS11972
E PepperellMASSACHUSETTS11988
S BarreMASSACHUSETTS12021
Warren 2MASSACHUSETTS12011
Ware RiverMASSACHUSETTS12022
BrentwoodNEW-HAMPSHIRE11986
DoverNEW-HAMPSHIRE11986
StraffordNEW-HAMPSHIRE12024
Quonset PtRHODE-ISLAND11966

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