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

Alder Flycatcher In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastAerial insectivores

Alder Flycatcher in New England / Mid-Atlantic Coast has surged: up 95% on the route-weighted index since 1971.

+95%Since 1971TrendPercent 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 →
35Routes 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 →
54YearsYears 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 →

No notable trend signals for Alder Flycatcher in New England / Mid-Atlantic Coast. See the full index history below.

Forecast

If the recent trend holds, Alder Flycatcher in New England / Mid-Atlantic Coast is projected to rise about 66% by 2029 — from 0.05 in 2024 to a central estimate of 0.09 (95% range 0.01–0.17). A 5-year backtest shows a typical error of ±97.9%, with 100% of held-out values landing inside the 95% band.

+66%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 →
0.09Projected 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 →
0.01–0.1795% 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 →
±97.9%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, Alder Flycatcher in New England / Mid-Atlantic Coast is projected to rise about 66% by 2029 — from 0.05 in 2024 to a central estimate of 0.09 (95% range 0.01–0.17). A 5-year backtest shows a typical error of ±97.9%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.090.010.17
20260.090.010.17
20270.090.010.17
20280.090.010.17
20290.090.010.17

Routes In New England / Mid-Atlantic Coast

Routes recording Alder 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 →
WarrenCONNECTICUT42011
BuckinghamCONNECTICUT22009
Woodstock 2CONNECTICUT22024
WarrenMASSACHUSETTS22008
WillimanticCONNECTICUT11996
No WoodburyCONNECTICUT12012
ShermanCONNECTICUT12005
Long HillCONNECTICUT11974
Mid HaddamCONNECTICUT11996
SouthingtonCONNECTICUT11974
Warren 2CONNECTICUT12024
GranbyCONNECTICUT12023
Cape NeddickMAINE11988
Kittery PtMAINE12017
WellfleetMASSACHUSETTS11987
NewburyportMASSACHUSETTS12010
MaynardMASSACHUSETTS11994
LittletonMASSACHUSETTS12009
PrincetonMASSACHUSETTS11976
E PepperellMASSACHUSETTS11993
BelchertownMASSACHUSETTS12022
S BarreMASSACHUSETTS12024
Gay HeadMASSACHUSETTS12019
Wellfleet 2MASSACHUSETTS12018
HoldenMASSACHUSETTS12016

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