BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

Pacific Wren In BCR 2

All regionsBCR 2Forest birds

Pacific Wren in BCR 2 has fallen sharply: down 51% on the route-weighted index since 1985.

-51%Since 1985TrendPercent 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 →
3Routes 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 →
35YearsYears 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 declinecomputed 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 →

Pacific Wren has fallen sharply in BCR 2: down 51% on the route-weighted index since 1985.

Pacific Wren In BCR 2 Population Forecast

If the recent trend holds, Pacific Wren in BCR 2 is projected to fall about 29% by 2029 — from 12 in 2024 to a central estimate of 8.5 (95% range 0.00–24). A 5-year backtest shows a typical error of ±32.3%, with 100% of held-out values landing inside the 95% band.

-29%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 →
8.5Projected 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 →
0.00–2495% 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 →
±32.3%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, Pacific Wren in BCR 2 is projected to fall about 29% by 2029 — from 12 in 2024 to a central estimate of 8.5 (95% range 0.00–24). A 5-year backtest shows a typical error of ±32.3%, with 100% of held-out values landing inside the 95% band.19832029
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 →
20258.20.0024
20268.30.0024
20278.40.0024
20288.40.0024
20298.50.0024

Routes In BCR 2

Routes recording Pacific Wren in BCR 2.
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 →
ChiniakALASKA612024
Kodiak 2ALASKA462024
KodiakALASKA121984

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