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

Brown Creeper In Sierra Nevada

All regionsSierra NevadaForest birds

Brown Creeper in Sierra Nevada has surged: up 131% on the route-weighted index since 1970.

+131%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 →
39Routes 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 →
57YearsYears 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 →

Brown Creeper has surged in Sierra Nevada: up 131% on the route-weighted index since 1970.

Brown Creeper In Sierra Nevada Population Forecast

If the recent trend holds, Brown Creeper in Sierra Nevada is projected to stay roughly flat through 2030, near 4.1 (95% range 1.4–6.8). A 5-year backtest shows a typical error of ±21.8%, with 100% of held-out values landing inside the 95% band.

+2%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 →
4.1Projected 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 →
1.4–6.895% 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 →
±21.8%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, Brown Creeper in Sierra Nevada is projected to stay roughly flat through 2030, near 4.1 (95% range 1.4–6.8). A 5-year backtest shows a typical error of ±21.8%, 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 →
20264.11.46.8
20274.11.46.8
20284.11.46.8
20294.11.46.8
20304.11.46.8

Routes In Sierra Nevada

Routes recording Brown Creeper 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 →
WestvilleCALIFORNIA182025
Last ChanceCALIFORNIA152019
LumberyardCALIFORNIA142025
Lassen ParkCALIFORNIA131989
Greenhorn MtCALIFORNIA122008
RivertonCALIFORNIA92025
Pollock PinesCALIFORNIA92025
Butte MeadowCALIFORNIA82014
LakeshoreCALIFORNIA82024
CoultervilleCALIFORNIA82019
ChilcootCALIFORNIA72024
Tahoe NfCALIFORNIA51994
JohnsvilleCALIFORNIA42025
Kings CanyonCALIFORNIA42024
Tuolumne GroveCALIFORNIA42025
Hat CreekCALIFORNIA42018
Little TruckeeCALIFORNIA42025
GeneseeCALIFORNIA32024
Higgins CornCALIFORNIA32024
ChesterCALIFORNIA32017
Eagle LakeCALIFORNIA22025
Bass LakeCALIFORNIA22018
GoumazCALIFORNIA22011
Meadow ValleyCALIFORNIA22025
Forest HillCALIFORNIA22022

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