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

Brown Thrasher In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastForest birds

Brown Thrasher in New England / Mid-Atlantic Coast has fallen sharply: down 58% on the route-weighted index since 1968.

-58%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 →
159Routes 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 declinecomputed 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 →

Brown Thrasher has fallen sharply in New England / Mid-Atlantic Coast: down 58% on the route-weighted index since 1968.

Brown Thrasher In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Brown Thrasher in New England / Mid-Atlantic Coast is projected to fall about 65% by 2030 — from 2.4 in 2025 to a central estimate of 0.85 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±57.4%, with 60% of held-out values landing inside the 95% band.

-65%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 →
0.85Projected 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 →
0.00–2.395% 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 →
±57.4%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, Brown Thrasher in New England / Mid-Atlantic Coast is projected to fall about 65% by 2030 — from 2.4 in 2025 to a central estimate of 0.85 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±57.4%, with 60% 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 →
20261.10.002.5
20271.00.002.5
20280.950.002.4
20290.900.002.4
20300.850.002.3

Routes In New England / Mid-Atlantic Coast

Routes recording Brown Thrasher 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 CreekMARYLAND202025
PomfretMARYLAND152024
Spraguetown 2NEW-JERSEY122007
TruhartVIRGINIA122024
MelitotaMARYLAND112025
BlackbirdDELAWARE102025
Tall TimbersMARYLAND92014
PomonkeyMARYLAND92025
NottinghamMARYLAND92025
Grove NeckMARYLAND91996
SharpsVIRGINIA92025
GloucesterVIRGINIA82025
La PlataMARYLAND72009
HongaMARYLAND72025
MadisonMARYLAND72025
Forest GroveMARYLAND72023
DeepwaterNEW-JERSEY71977
FredericaDELAWARE62025
HughesvilleMARYLAND62025
CokesburyMARYLAND62025
Port RoyalVIRGINIA62025
Milton 2DELAWARE52025
Pepperbox 2DELAWARE52025
St. George'S IslandMARYLAND52017
WalnutMARYLAND52024

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