BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Oak Titmouse

ParidaeForest birdsBaeolophus inornatus

Oak Titmouse has risen sharply: up 64% on the route-weighted index since 1970.

+64%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 →
166RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Oak Titmouse

The Oak Titmouse (Baeolophus inornatus) is a North American member of the Chickadees & Titmice (Paridae). In this analysis it is grouped with the forest birds.

Size
4.5–6 in long (11–15 cm) — a tiny, active songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 166 Breeding Bird Survey routes across 2 states, most concentrated in the Coastal California.
Family
Paridae · Forest birds

Notable Oak Titmouse TrendsNotable 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 →

Oak Titmouse has risen sharply in surveyed states: up 64% on the route-weighted index since 1970.

Oak Titmouse Population Forecast

If the recent trend holds, Oak Titmouse is projected to fall about 13% by 2029 — from 0.24 in 2024 to a central estimate of 0.21 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±15.6%, with 100% of held-out values landing inside the 95% band.

-13%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 →
0.21Projected 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 →
0.00–0.4395% 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 →
±15.6%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 is projected to fall about 13% by 2029 — from 0.24 in 2024 to a central estimate of 0.21 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±15.6%, 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 →
20250.220.000.45
20260.220.000.44
20270.210.000.44
20280.210.000.43
20290.210.000.43

Where the Oak Titmouse Is Detected

BBS routes recording Oak Titmouse, sized by most recent count.

Oak Titmouse Population Trend by State

Oak Titmouse population trend by state.
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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
California+48%1970156
Oregon-68%197110

Oak Titmouse Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Oak Titmouse population trend by Bird Conservation Region.
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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-50%197030
Great Basin+356%19809
Sierra Nevada-58%197120
Coastal California+61%1970102
Sonoran and Mojave Deserts-45%19735

Oak Titmouse Conservation Status

Our route-weighted index shows it up about 64% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.