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

Rock Wren In Sierra Nevada

All regionsSierra NevadaForest birds

Rock Wren in Sierra Nevada has surged: up 145% on the route-weighted index since 1971.

+145%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 →
23Routes 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 →
55YearsYears 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 →

Rock Wren has surged in Sierra Nevada: up 145% on the route-weighted index since 1971.

Rock Wren In Sierra Nevada Population Forecast

If the recent trend holds, Rock Wren in Sierra Nevada is projected to fall about 54% by 2030 — from 1.6 in 2025 to a central estimate of 0.75 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±195.8%, with 60% of held-out values landing inside the 95% band.

-54%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 →
0.75Projected 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 →
0.00–1.795% 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 →
±195.8%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, Rock Wren in Sierra Nevada is projected to fall about 54% by 2030 — from 1.6 in 2025 to a central estimate of 0.75 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±195.8%, with 60% of held-out values landing inside the 95% band.19692030
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 →
20260.720.001.7
20270.720.001.7
20280.730.001.7
20290.740.001.7
20300.750.001.7

Routes In Sierra Nevada

Routes recording Rock Wren 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 →
Eagle LakeCALIFORNIA162025
Pine MountainCALIFORNIA112017
ChilcootCALIFORNIA82024
WoodfordsCALIFORNIA72025
Hat CreekCALIFORNIA62018
Tuolumne GroveCALIFORNIA32025
LakeshoreCALIFORNIA32024
Kings CanyonCALIFORNIA21990
GeneseeCALIFORNIA22024
Meadow ValleyCALIFORNIA22022
Last ChanceCALIFORNIA22019
WestvilleCALIFORNIA12017
DardanelleCALIFORNIA12014
Bass LakeCALIFORNIA12016
LumberyardCALIFORNIA11979
RivertonCALIFORNIA12007
GoumazCALIFORNIA12011
PaxtonCALIFORNIA12025
Forest HillCALIFORNIA12025
Pollock PinesCALIFORNIA12025
KernvilleCALIFORNIA12008
CrestviewCALIFORNIA12024
StrawberryCALIFORNIA12015

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