BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Oak Titmouse In Sierra Nevada

All regionsSierra NevadaForest birds

Oak Titmouse in Sierra Nevada has fallen sharply: down 55% on the route-weighted index since 1971.

-55%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 →
20Routes 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 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 →

Oak Titmouse has fallen sharply in Sierra Nevada: down 55% on the route-weighted index since 1971.

Oak Titmouse In Sierra Nevada Population Forecast

If the recent trend holds, Oak Titmouse in Sierra Nevada is projected to rise about 84% by 2030 — from 0.83 in 2025 to a central estimate of 1.5 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±125.2%, with 100% of held-out values landing inside the 95% band.

+84%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 →
1.5Projected 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 →
0.00–4.195% 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 →
±125.2%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, Oak Titmouse in Sierra Nevada is projected to rise about 84% by 2030 — from 0.83 in 2025 to a central estimate of 1.5 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±125.2%, with 100% 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 →
20261.60.004.2
20271.60.004.2
20281.60.004.2
20291.60.004.1
20301.50.004.1

Routes In Sierra Nevada

Routes recording Oak Titmouse in Sierra Nevada.
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 →
Silver CityCALIFORNIA542013
Bass LakeCALIFORNIA382019
Greenhorn MtCALIFORNIA172008
KernvilleCALIFORNIA102008
WawonaCALIFORNIA82025
Higgins CornCALIFORNIA72025
Forest HillCALIFORNIA42014
CoultervilleCALIFORNIA42019
LakeshoreCALIFORNIA22009
PlacervilleCALIFORNIA21997
Forest Hill 2CALIFORNIA22005
Cottage SpgsCALIFORNIA11975
JohnsvilleCALIFORNIA11984
WoodfordsCALIFORNIA12024
LumberyardCALIFORNIA11976
Kings CanyonCALIFORNIA12024
Tuolumne GroveCALIFORNIA12022
DownievilleCALIFORNIA12007
Pine MountainCALIFORNIA12002
StrawberryCALIFORNIA12010

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