BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Ruby-crowned Kinglet In Sierra Nevada

All regionsSierra NevadaForest birds

Ruby-crowned Kinglet in Sierra Nevada has collapsed: down 84% on the route-weighted index since 1972.

-84%Since 1972TrendPercent 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 →
25Routes 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 →
41YearsYears 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 →

Ruby-crowned Kinglet has collapsed in Sierra Nevada: down 84% on the route-weighted index since 1972.

Ruby-crowned Kinglet In Sierra Nevada Population Forecast

If the recent trend holds, Ruby-crowned Kinglet in Sierra Nevada is projected to fall about 100% by 2029 — from 0.05 in 2024 to a central estimate of 0.00 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±344.9%, with 80% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.8695% 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 →
±344.9%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, Ruby-crowned Kinglet in Sierra Nevada is projected to fall about 100% by 2029 — from 0.05 in 2024 to a central estimate of 0.00 (95% range 0.00–0.86). A 5-year backtest shows a typical error of ±344.9%, with 80% 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 →
20250.000.000.86
20260.000.000.86
20270.000.000.86
20280.000.000.86
20290.000.000.86

Routes In Sierra Nevada

Routes recording Ruby-crowned Kinglet 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 →
GeneseeCALIFORNIA82019
JohnsvilleCALIFORNIA62019
Last ChanceCALIFORNIA42019
Hat CreekCALIFORNIA31991
LakeshoreCALIFORNIA32004
Meadow ValleyCALIFORNIA32021
Cottage SpgsCALIFORNIA21968
DardanelleCALIFORNIA22006
Bass LakeCALIFORNIA21981
LumberyardCALIFORNIA21997
Silver CityCALIFORNIA21980
Kings CanyonCALIFORNIA21985
Tahoe NfCALIFORNIA21993
Lassen ParkCALIFORNIA11978
Eagle LakeCALIFORNIA11987
WestvilleCALIFORNIA12021
WoodfordsCALIFORNIA12001
SattleyCALIFORNIA12006
Butte MeadowCALIFORNIA11979
DownievilleCALIFORNIA12024
RivertonCALIFORNIA11991
GoumazCALIFORNIA11999
Little TruckeeCALIFORNIA11997
Forest HillCALIFORNIA12008
Pollock PinesCALIFORNIA12008

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.