BirdAnalyst
Species · Massachusetts · BBS 2025 Release · 1966–2024

Common Tern Population Trend in Massachusetts

All statesWetland birds

Common Tern in Massachusetts has collapsed: down 75% on the route-weighted index since 1969.

-75%Since 1969
6Routes In State
41Years

Notable Common Tern Trends in Massachusetts

long arc declinecomputed index

Common Tern has collapsed in Massachusetts: down 75% on the route-weighted index since 1969.

Common Tern Population Forecast in Massachusetts

If the recent trend holds, Common Tern in Massachusetts is projected to fall about 97% by 2029 — from 0.47 in 2024 to a central estimate of 0.01 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±138.1%, with 100% of held-out values landing inside the 95% band.

-97%Change by 2029
0.01Projected 2029 index
0.00–2.395% range
±138.1%Backtest error
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 index95% low95% high
20250.100.002.4
20260.080.002.3
20270.060.002.3
20280.040.002.3
20290.010.002.3

Common Tern Survey Routes in Massachusetts

Routes recording Common Tern in Massachusetts.
Chilmark6419831969
Gay Head720241996
Newburyport320171968
E Dennis120181969
Wellfleet119971966
Cape Cod Ns119981989

Common Tern Population Trend in Other States

alabamaalaskaconnecticutdelawarefloridaidahoindianalouisianamainemarylandmichiganminnesotamontananew-jerseynew-yorknorth-carolinanorth-dakotaohiorhode-islandsouth-dakotatexasvermontvirginiawashingtonwisconsinwyoming

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