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

Marsh Wren Population Trend in Washington

All statesForest birds

Marsh Wren in Washington has surged: up 150% on the route-weighted index since 1970.

+150%Since 1970
49Routes In State
53Years

Notable Marsh Wren Trends in Washington

long arc increasecomputed index

Marsh Wren has surged in Washington: up 150% on the route-weighted index since 1970.

Marsh Wren Population Forecast in Washington

If the recent trend holds, Marsh Wren in Washington is projected to rise about 86% by 2029 — from 0.53 in 2024 to a central estimate of 0.98 (95% range 0.58–1.4). A 5-year backtest shows a typical error of ±90.3%, with 20% of held-out values landing inside the 95% band.

+86%Change by 2029
0.98Projected 2029 index
0.58–1.495% range
±90.3%Backtest error
19682029
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
20250.920.531.3
20260.940.541.3
20270.950.561.3
20280.960.571.4
20290.980.581.4

Marsh Wren Survey Routes in Washington

Routes recording Marsh Wren in Washington.
Reardan1920142000
Mendota 31020242005
Mendota 2920001989
Raymond 2520242023
Raymond520211994
Brewster420152000
Issaquah419861980
Ardenvoir419681968
Mcchord420151996
Tonasket420102007
South Elma420241991
Taholah320181975
Ewan320191985
Potholes320231996
Mukilteo320191994
Warm Beach 2320222018
Ewan 2220242024
Moses Lake220221975
Bunker Hill220241969
Kendall220181984
Cusick220182002
Mendota219861981
Scootney Reservoir220242009
Malden220242003
Ozette120031985

Marsh Wren Population Trend in Other States

alabamaarizonacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawisconsinwyoming

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