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Species · BCR 4 · BBS 2025 Release · 1966–2024

Ruby-crowned Kinglet In BCR 4

All regionsBCR 4Forest birds

Ruby-crowned Kinglet in BCR 4 has edged up: up 25% on the route-weighted index since 1982.

+25%Since 1982TrendPercent 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 →
65Routes 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 →
44YearsYears 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 →

No notable trend signals for Ruby-crowned Kinglet in BCR 4. See the full index history below.

Ruby-crowned Kinglet In BCR 4 Population Forecast

If the recent trend holds, Ruby-crowned Kinglet in BCR 4 is projected to rise about 56% by 2029 — from 6.4 in 2024 to a central estimate of 10 (95% range 4.3–16). A 5-year backtest shows a typical error of ±32.1%, with 100% of held-out values landing inside the 95% band.

+56%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 →
10Projected 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 →
4.3–1695% 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 →
±32.1%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 BCR 4 is projected to rise about 56% by 2029 — from 6.4 in 2024 to a central estimate of 10 (95% range 4.3–16). A 5-year backtest shows a typical error of ±32.1%, 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 →
2025104.216
2026104.216
2027104.316
2028104.316
2029104.316

Routes In BCR 4

Routes recording Ruby-crowned Kinglet in BCR 4.
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 →
SourdoughALASKA442024
HomerALASKA281982
KalifonskyALASKA252023
Skilak LakeALASKA231985
Ft. RichrdsnALASKA202023
Kanuti LakeALASKA202024
PetersvilleALASKA192024
RubyALASKA192024
L SalchaALASKA182023
KuskulanaALASKA182024
Goose BayALASKA171982
Koyukuk Riv.ALASKA162001
Tower BluffsALASKA132023
NorthwayALASKA132023
TatalinaALASKA132019
Chatanika RALASKA122023
Anchor RiverALASKA122024
ChistochinaALASKA112024
Lake LouiseALASKA112014
WillowALASKA102024
Chena Hot Spring 2ALASKA102024
Mccarthy Rd2ALASKA92024
SlanaALASKA82022
ToklatALASKA82013
Galena (Short)ALASKA82024

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