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

Willow Flycatcher In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Willow Flycatcher in New England / Mid-Atlantic Coast has surged: up 275% on the route-weighted index since 1968.

+275%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 →
86Routes 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 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 →

Willow Flycatcher has surged in New England / Mid-Atlantic Coast: up 275% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Willow Flycatcher in New England / Mid-Atlantic Coast is projected to rise about 51% by 2029 — from 0.22 in 2024 to a central estimate of 0.34 (95% range 0.19–0.49). A 5-year backtest shows a typical error of ±107.1%, with 20% of held-out values landing inside the 95% band.

+51%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 →
0.34Projected 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 →
0.19–0.4995% 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 →
±107.1%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 →
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 →
20250.320.170.47
20260.330.170.48
20270.330.180.48
20280.340.180.49
20290.340.190.49

Routes In New England / Mid-Atlantic Coast

Routes recording Willow Flycatcher 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 →
N. AndoverMASSACHUSETTS72024
WarrenCONNECTICUT42011
GranbyCONNECTICUT42024
WarrenMASSACHUSETTS42009
DoverNEW-HAMPSHIRE42023
Chincoteag WVIRGINIA31998
ShermanCONNECTICUT22018
DanburyCONNECTICUT22017
Cape NeddickMAINE22012
CheltenhamMARYLAND22003
HongaMARYLAND22003
Fair HillMARYLAND21995
E DennisMASSACHUSETTS22014
BelchertownMASSACHUSETTS22019
East KingstonNEW-HAMPSHIRE22019
Ocean CityNEW-JERSEY22024
Jones BeachNEW-YORK22006
ShannockRHODE-ISLAND22019
Cape CharlesVIRGINIA21997
MysticCONNECTICUT12023
BuckinghamCONNECTICUT12015
UncasvilleCONNECTICUT12023
WoodstockCONNECTICUT12005
WestbrookCONNECTICUT11993
WillimanticCONNECTICUT12005

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