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

Marsh Wren Population Trend in Connecticut

All statesForest birds

Marsh Wren in Connecticut has surged: up 445% on the route-weighted index since 1977.

+445%Since 1977
7Routes In State
34Years

Notable Marsh Wren Trends in Connecticut

long arc increasecomputed index

Marsh Wren has surged in Connecticut: up 444% on the route-weighted index since 1977.

Marsh Wren Population Forecast in Connecticut

If the recent trend holds, Marsh Wren in Connecticut is projected to fall about 12% by 2029 — from 0.78 in 2024 to a central estimate of 0.68 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±69.5%, with 100% of held-out values landing inside the 95% band.

-12%Change by 2029
0.68Projected 2029 index
0.00–1.695% range
±69.5%Backtest error
19732029
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
20250.670.001.6
20260.680.001.6
20270.680.001.6
20280.680.001.6
20290.680.001.6

Marsh Wren Survey Routes in Connecticut

Routes recording Marsh Wren in Connecticut.
Westbrook520241975
Warren 2220242024
Mystic120172017
Buckingham120142014
Woodstock119951986
Danbury119731973
Mid Haddam119801980

Marsh Wren Population Trend in Other States

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

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