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

Carolina Wren In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Carolina Wren in New England / Mid-Atlantic Coast has surged: up 928% on the route-weighted index since 1968.

+928%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 →
160Routes 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 →

Carolina Wren has surged in New England / Mid-Atlantic Coast: up 928% on the route-weighted index since 1968.

Carolina Wren In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Carolina Wren in New England / Mid-Atlantic Coast is projected to fall about 24% by 2029 — from 27 in 2024 to a central estimate of 21 (95% range 15–27). A 5-year backtest shows a typical error of ±26.3%, with 40% of held-out values landing inside the 95% band.

-24%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 →
21Projected 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 →
15–2795% 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 →
±26.3%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, Carolina Wren in New England / Mid-Atlantic Coast is projected to fall about 24% by 2029 — from 27 in 2024 to a central estimate of 21 (95% range 15–27). A 5-year backtest shows a typical error of ±26.3%, with 40% 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 →
2025201426
2026201426
2027201427
2028211427
2029211527

Routes In New England / Mid-Atlantic Coast

Routes recording Carolina Wren 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 →
Island CreekMARYLAND1092024
CokesburyMARYLAND1022024
HarringtonDELAWARE822024
Pepperbox 2DELAWARE772024
HongaMARYLAND662024
MadisonMARYLAND632024
Forest GroveMARYLAND632023
DavidsnvilleMARYLAND632024
Cape May ChNEW-JERSEY622013
QuinbyVIRGINIA572024
MillingtonMARYLAND512024
Piney NeckMARYLAND512024
Port RoyalVIRGINIA492019
WalnutMARYLAND482024
Holleyville 2DELAWARE472024
La PlataMARYLAND462009
JessupMARYLAND462024
ManorvilleNEW-YORK462024
PepperboxDELAWARE442016
PomonkeyMARYLAND442024
Milton 2DELAWARE432017
MarionMASSACHUSETTS422024
HolleyvilleDELAWARE412004
MillsboroDELAWARE412024
Furnace TownMARYLAND402024

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