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

Marsh Wren Population Trend in Massachusetts

All statesForest birds

Marsh Wren in Massachusetts has surged: up 350% on the route-weighted index since 1970.

+350%Since 1970
6Routes In State
42Years

Notable Marsh Wren Trends in Massachusetts

long arc increasecomputed index

Marsh Wren has surged in Massachusetts: up 350% on the route-weighted index since 1970.

Marsh Wren Population Forecast in Massachusetts

If the recent trend holds, Marsh Wren in Massachusetts is projected to rise about 247% by 2029 — from 0.13 in 2024 to a central estimate of 0.46 (95% range 0.11–0.81). A 5-year backtest shows a typical error of ±125.9%, with 100% of held-out values landing inside the 95% band.

+247%Change by 2029
0.46Projected 2029 index
0.11–0.8195% range
±125.9%Backtest error
19672029
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
20250.440.090.79
20260.440.090.79
20270.450.100.80
20280.460.100.81
20290.460.110.81

Marsh Wren Survey Routes in Massachusetts

Routes recording Marsh Wren in Massachusetts.
Newburyport1220221967
Brockton219871976
N. Andover220242007
Mansfield119701970
Warren 2120212021
Sheffield120132013

Marsh Wren Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwisconsinwyoming

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