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

Varied Thrush In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Varied Thrush in Northern Pacific Rainforest has surged: up 366% on the route-weighted index since 1970.

+366%Since 1970TrendPercent 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 →
116Routes 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 →

Varied Thrush has surged in Northern Pacific Rainforest: up 366% on the route-weighted index since 1970.

Varied Thrush In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Varied Thrush in Northern Pacific Rainforest is projected to rise about 36% by 2029 — from 14 in 2024 to a central estimate of 19 (95% range 14–24). A 5-year backtest shows a typical error of ±25.1%, with 100% of held-out values landing inside the 95% band.

+36%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 →
19Projected 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 →
14–2495% 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 →
±25.1%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, Varied Thrush in Northern Pacific Rainforest is projected to rise about 36% by 2029 — from 14 in 2024 to a central estimate of 19 (95% range 14–24). A 5-year backtest shows a typical error of ±25.1%, with 100% of held-out values landing inside the 95% band.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 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 →
2025181323
2026181324
2027191324
2028191424
2029191424

Routes In Northern Pacific Rainforest

Routes recording Varied Thrush 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 →
Chichagof IsALASKA1552024
HoonahALASKA1452024
Copper RiverALASKA982011
SewardALASKA951992
Yakutat (Short)ALASKA941984
Kuiu IslandALASKA932010
PetersburgALASKA791987
Stikine RiverALASKA692024
Redwood N.P. 2CALIFORNIA672013
Harlequin L.ALASKA592024
HyderALASKA592009
Sitka (Short)ALASKA501992
Mitkof IsleALASKA492024
Redwood N.P.CALIFORNIA492010
HopeALASKA472024
Whale PassALASKA462024
CraigALASKA452024
Thorne Bay 2ALASKA432024
Zimovia StrtALASKA402024
Moose PassALASKA391992
Thorne BayALASKA362012
Mt RainierWASHINGTON342021
SitkaALASKA312024
CordovaALASKA302024
JuneauALASKA292024

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