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

Double-crested Cormorant In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Double-crested Cormorant in New England / Mid-Atlantic Coast has surged: up 20× on the route-weighted index since 1970.

20×Since 1970TrendPercent 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 →
111Routes 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 →
57YearsYears 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 Double-crested Cormorant in New England / Mid-Atlantic Coast. See the full index history below.

Double-crested Cormorant In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Double-crested Cormorant in New England / Mid-Atlantic Coast is projected to rise about 194% by 2030 — from 0.50 in 2025 to a central estimate of 1.5 (95% range 0.45–2.5). A 5-year backtest shows a typical error of ±162.2%, with 60% of held-out values landing inside the 95% band.

+194%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 →
1.5Projected 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 →
0.45–2.595% 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 →
±162.2%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, Double-crested Cormorant in New England / Mid-Atlantic Coast is projected to rise about 194% by 2030 — from 0.50 in 2025 to a central estimate of 1.5 (95% range 0.45–2.5). A 5-year backtest shows a typical error of ±162.2%, 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 →
20261.40.382.4
20271.40.392.4
20281.40.412.5
20291.40.432.5
20301.50.452.5

Routes In New England / Mid-Atlantic Coast

Routes recording Double-crested Cormorant 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 →
ShannockRHODE-ISLAND542023
PomfretMARYLAND301998
St. George'S IslandMARYLAND252017
Port RoyalVIRGINIA242019
ChilmarkMASSACHUSETTS221983
HughesvilleMARYLAND202009
NortheastMARYLAND202008
SharpsVIRGINIA132013
Cape CharlesVIRGINIA122018
NewburyportMASSACHUSETTS112022
PedricktownNEW-JERSEY102006
Chincoteag WVIRGINIA102022
Kittery PtMAINE92025
LittletonMASSACHUSETTS92000
HarringtonDELAWARE82025
DanburyCONNECTICUT72013
FredericaDELAWARE62007
Ocean CityNEW-JERSEY62025
Block IslandRHODE-ISLAND62010
Cape Cod NsMASSACHUSETTS51996
WesthamptonNEW-YORK52006
Quonset PtRHODE-ISLAND52022
Bethany BchDELAWARE41990
BrocktonMASSACHUSETTS42018
Bennett MillNEW-JERSEY41998

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