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Species · Maryland · BBS 2025 Release · 1966–2024

Marsh Wren Population Trend in Maryland

All statesForest birds

Marsh Wren in Maryland has collapsed: down 82% on the route-weighted index since 1968.

-82%Since 1968
10Routes In State
58Years

Notable Marsh Wren Trends in Maryland

long arc declinecomputed index

Marsh Wren has collapsed in Maryland: down 82% on the route-weighted index since 1968.

Marsh Wren Population Forecast in Maryland

If the recent trend holds, Marsh Wren in Maryland is projected to fall about 100% by 2029 — from 0.19 in 2024 to a central estimate of 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±174.7%, with 80% of held-out values landing inside the 95% band.

-100%Change by 2029
0.00Projected 2029 index
0.00–0.3495% range
±174.7%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
20250.000.000.34
20260.000.000.34
20270.000.000.34
20280.000.000.34
20290.000.000.34

Marsh Wren Survey Routes in Maryland

Routes recording Marsh Wren in Maryland.
Honga420241966
Madison420181966
Cokesbury420241967
Piney Neck319801967
Harmony319681966
Berlin320052005
Elkton219881966
Broomes Isl219661966
Melitota119821966
Jones119681968

Marsh Wren Population Trend in Other States

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

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