BirdAnalyst
Species · BCR 5 · BBS 2026 Release · 1966–2025

Marsh Wren In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Marsh Wren in Northern Pacific Rainforest has surged: up 613% on the route-weighted index since 1971.

+613%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 →
47Routes 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 →
56YearsYears 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 613% 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 fall about 18% by 2030 — from 0.69 in 2025 to a central estimate of 0.56 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±11.5%, with 100% of held-out values landing inside the 95% band.

-18%Change by 2030TrendPercent 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 →
0.56Projected 2030 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 →
±11.5%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 fall about 18% by 2030 — from 0.69 in 2025 to a central estimate of 0.56 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±11.5%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.560.001.1
20270.560.001.1
20280.560.001.1
20290.560.001.1
20300.560.001.1

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 →
GlasgowOREGON112025
Mendota 2WASHINGTON92000
Bunker HillWASHINGTON82025
EverettWASHINGTON72025
Redwood N.P.CALIFORNIA52010
RaymondWASHINGTON52021
MukilteoWASHINGTON52025
Raymond 2WASHINGTON52024
Mendota 3WASHINGTON52025
Bodega BayCALIFORNIA42021
Redwood N.P. 2CALIFORNIA42013
IssaquahWASHINGTON41986
South ElmaWASHINGTON42024
McchordWASHINGTON42015
HauserOREGON31985
Nicolai Mtn.OREGON32025
CoquilleOREGON32025
TaholahWASHINGTON32018
Warm Beach 2WASHINGTON32022
Crescent CtyCALIFORNIA22024
WedderburnOREGON21997
SvensenOREGON21992
SalemOREGON22016
MendotaWASHINGTON21986
CarnationWASHINGTON22025

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.