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Species · BCR 5 · BBS 2025 Release · 1966–2024

Marsh Wren In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Marsh Wren in Northern Pacific Rainforest has surged: up 582% on the route-weighted index since 1971.

+582%Since 1971TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
46Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Marsh Wren has surged in Northern Pacific Rainforest: up 581% on the route-weighted index since 1971.

Marsh Wren In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Marsh Wren in Northern Pacific Rainforest is projected to stay roughly flat through 2029, near 0.55 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.

-1%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.55Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±9%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Marsh Wren in Northern Pacific Rainforest is projected to stay roughly flat through 2029, near 0.55 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±9%, with 100% of held-out values landing inside the 95% band.19692029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.550.001.1
20260.550.001.1
20270.550.001.1
20280.550.001.1
20290.550.001.1

Routes In Northern Pacific Rainforest

Routes recording Marsh Wren in Northern Pacific Rainforest.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Mendota 3WASHINGTON102024
Mendota 2WASHINGTON92000
Nicolai Mtn.OREGON82024
Redwood N.P.CALIFORNIA52010
GlasgowOREGON52024
RaymondWASHINGTON52021
Raymond 2WASHINGTON52024
Bodega BayCALIFORNIA42021
Redwood N.P. 2CALIFORNIA42013
IssaquahWASHINGTON41986
South ElmaWASHINGTON42024
McchordWASHINGTON42015
HauserOREGON31985
AdairOREGON32022
CoquilleOREGON32024
TaholahWASHINGTON32018
MukilteoWASHINGTON32019
Warm Beach 2WASHINGTON32022
Crescent CtyCALIFORNIA22024
WedderburnOREGON21997
SvensenOREGON21992
SalemOREGON22016
Bunker HillWASHINGTON22024
MendotaWASHINGTON21986
HullvilleCALIFORNIA12013

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