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Species · California · BBS 2025 Release · 1966–2024

Hutton's Vireo Population Trend in California

All statesForest birds

Hutton's Vireo in California has edged up: up 17% on the route-weighted index since 1970.

+17%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 →
140Routes In StateSurvey 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 Hutton's Vireo Trends in CaliforniaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Hutton's Vireo in California. See the full index history below.

Hutton's Vireo Population Forecast in California

If the recent trend holds, Hutton's Vireo in California is projected to rise about 143% by 2029 — from 0.65 in 2024 to a central estimate of 1.6 (95% range 0.72–2.4). A 5-year backtest shows a typical error of ±164.5%, with 0% of held-out values landing inside the 95% band.

+143%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 →
1.6Projected 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 →
0.72–2.495% 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 →
±164.5%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, Hutton's Vireo in California is projected to rise about 143% by 2029 — from 0.65 in 2024 to a central estimate of 1.6 (95% range 0.72–2.4). A 5-year backtest shows a typical error of ±164.5%, with 0% 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 →
20251.50.672.4
20261.50.692.4
20271.50.702.4
20281.60.712.4
20291.60.722.4

Hutton's Vireo Survey Routes in California

Routes recording Hutton's Vireo in California.
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 →
Adelaida1520151970
Martins Fy1120091976
Alderpoint920121975
Coulterville920191997
Hiouchi820142002
Redwood N.P. 2820132012
Forest Hill820221997
Fish Rock720141968
Shasta Lake720241972
Silver City720131981
Santa Cruz I719881988
Korbel720241972
French Gulch720102002
Forest Hill 2620052005
Cecilville620171999
Colma519721968
Elsinore Mtn520241972
Tehama520221975
Redwood N.P.520102006
Honeydew420171968
Calpella419861968
Rumsey420081976
Orleans420121972
Waterman Gap420241972
Tres Pinos 2420112005

Hutton's Vireo Population Trend in Other States

arizonanew-mexicooregontexaswashington

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