BirdAnalyst
Guild · California · BBS 2026 Release · 1966–2025

Forest Birds In California

All statesCalifornia

94 species in this guild. As a group they are +5%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1970.

Guild SignalsNotable 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 forest birds in California. See the full index history below.

Forest Birds In California Population Forecast

If the recent trend holds, Forest birds in California is projected to rise about 14% by 2030 — from 2.3 in 2025 to a central estimate of 2.6 (95% range 2.1–3.0). A 5-year backtest shows a typical error of ±26.1%, with 0% of held-out values landing inside the 95% band.

+14%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 →
2.6Projected 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 →
2.1–3.095% 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 →
±26.1%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, Forest birds in California is projected to rise about 14% by 2030 — from 2.3 in 2025 to a central estimate of 2.6 (95% range 2.1–3.0). A 5-year backtest shows a typical error of ±26.1%, with 0% of held-out values landing inside the 95% band.19682030
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 →
20262.62.13.0
20272.62.13.0
20282.62.13.0
20292.62.13.0
20302.62.13.0

Member Species In California

Forest birds species in California.
TrendPercent 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 →
Scott's OrioleIcteridae-84%
Gray VireoVireonidae-83%
Clark's NutcrackerCorvidae-77%
Pygmy NuthatchSittidae-74%
Plumbeous VireoVireonidae-70%
Varied ThrushTurdidae-66%
Ruby-crowned KingletRegulidae-65%
Pine SiskinFringillidae-57%
Lewis's WoodpeckerPicidae-56%
Wilson's WarblerParulidae-55%
White-crowned SparrowPasserellidae-55%
BushtitAegithalidae-52%
Chipping SparrowPasserellidae-51%
Cassin's FinchFringillidae-50%
Black-chinned HummingbirdTrochilidae-46%
Calliope HummingbirdTrochilidae-46%
Allen's HummingbirdTrochilidae-43%
Canada JayCorvidae-42%
Chestnut-backed ChickadeeParidae-39%
Evening GrosbeakFringillidae-38%
Bullock's OrioleIcteridae-38%
Lincoln's SparrowPasserellidae-35%
WrentitSylviidae-27%
Pine GrosbeakFringillidae-24%
Summer TanagerCardinalidae-22%
Indigo BuntingCardinalidae-22%
Broad-tailed HummingbirdTrochilidae-21%
Cedar WaxwingBombycillidae-18%
California Scrub-JayCorvidae-18%
Western BluebirdTurdidae-17%
Purple FinchFringillidae-17%
Yellow-breasted ChatIcteriidae-8%
Woodhouse's Scrub-JayCorvidae-8%
Black-headed GrosbeakCardinalidae-8%
Mountain BluebirdTurdidae-5%
Swainson's ThrushTurdidae-4%
Juniper TitmouseParidae-3%
Steller's JayCorvidae+5%
American GoldfinchFringillidae+7%
Canyon WrenTroglodytidae+9%
Townsend's SolitaireTurdidae+12%
Hutton's VireoVireonidae+15%
Bewick's WrenTroglodytidae+16%
Costa's HummingbirdTrochilidae+16%
Lawrence's GoldfinchFringillidae+21%
Hermit ThrushTurdidae+21%
Orange-crowned WarblerParulidae+24%
Pinyon JayCorvidae+25%
Northern House WrenTroglodytidae+26%
Rufous HummingbirdTrochilidae+27%
Yellow WarblerParulidae+30%
Mountain ChickadeeParidae+32%
Spotted TowheePasserellidae+32%
Warbling VireoVireonidae+34%
American RobinTurdidae+34%
Downy WoodpeckerPicidae+36%
Song SparrowPasserellidae+45%
Lazuli BuntingCardinalidae+46%
Oak TitmouseParidae+47%
Nuttall's WoodpeckerPicidae+48%
Lesser GoldfinchFringillidae+50%
Blue GrosbeakCardinalidae+50%
Acorn WoodpeckerPicidae+51%
White-breasted NuthatchSittidae+51%
California GnatcatcherPolioptilidae+58%
Rock WrenTroglodytidae+75%
Ladder-backed WoodpeckerPicidae+80%
Western TanagerCardinalidae+85%
Band-tailed PigeonColumbidae+87%
Red-breasted SapsuckerPicidae+90%
Williamson's SapsuckerPicidae+90%
Green-tailed TowheePasserellidae+97%
Black-throated Gray WarblerParulidae+101%
Hairy WoodpeckerPicidae+112%
White-headed WoodpeckerPicidae+114%
Anna's HummingbirdTrochilidae+137%
Black-capped ChickadeeParidae+194%
Fox SparrowPasserellidae+205%
Black-backed WoodpeckerPicidae+217%
MacGillivray's WarblerParulidae+241%
Pileated WoodpeckerPicidae+243%
Cassin's VireoVireonidae+297%
Red CrossbillFringillidae+314%
Nashville WarblerParulidae+319%
Brown CreeperCerthiidae+329%
Red-breasted NuthatchSittidae+346%
Hooded OrioleIcteridae+358%
Hermit WarblerParulidae+420%
Pacific WrenTroglodytidae+460%
Blue-gray GnatcatcherPolioptilidae+473%
Golden-crowned KingletRegulidae+669%
Marsh WrenTroglodytidae+958%
Common YellowthroatParulidae+999%
Bell's VireoVireonidae12×

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