BirdAnalyst
Species · BCR 30 · BBS 2026 Release · 1966–2025

Prothonotary Warbler In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Prothonotary Warbler in New England / Mid-Atlantic Coast has surged: up 151% on the route-weighted index since 1968.

+151%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 →
67Routes 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 →
59YearsYears 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 →

Prothonotary Warbler has surged in New England / Mid-Atlantic Coast: up 150% on the route-weighted index since 1968.

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

If the recent trend holds, Prothonotary Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2030, near 0.63 (95% range 0.43–0.83). A 5-year backtest shows a typical error of ±16%, with 80% of held-out values landing inside the 95% band.

-5%Change by 2030TrendPercent 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 →
0.63Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.43–0.8395% 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 →
±16%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, Prothonotary Warbler in New England / Mid-Atlantic Coast is projected to stay roughly flat through 2030, near 0.63 (95% range 0.43–0.83). A 5-year backtest shows a typical error of ±16%, with 80% of held-out values landing inside the 95% band.19662030
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 →
20260.610.410.81
20270.610.410.81
20280.620.420.82
20290.620.420.83
20300.630.430.83

Routes In New England / Mid-Atlantic Coast

Routes recording Prothonotary 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 →
Furnace TownMARYLAND112025
Pepperbox 2DELAWARE102025
PepperboxDELAWARE42016
BerlinMARYLAND42025
BrandonVIRGINIA42025
PomonkeyMARYLAND32025
CokesburyMARYLAND32025
SinepuxentMARYLAND31977
Snow HillMARYLAND31976
Cape May ChNEW-JERSEY32011
Piney NeckMARYLAND22017
HarmonyMARYLAND22017
DavidsnvilleMARYLAND22023
Island CreekMARYLAND22024
IndiantownMARYLAND22014
PomonaNEW-JERSEY22025
Estell ManorNEW-JERSEY22025
PedricktownNEW-JERSEY22010
WinslowNEW-JERSEY22025
SharpsVIRGINIA22022
Colonial PkyVIRGINIA21997
Chincoteag WVIRGINIA22015
Mt PleasantDELAWARE11968
WilmingtonDELAWARE12005
HarringtonDELAWARE12025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.