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Species · BCR 4 · BBS 2026 Release · 1966–2025

Ruby-crowned Kinglet In BCR 4

All regionsBCR 4Forest birds

Ruby-crowned Kinglet in BCR 4 has edged up: up 23% on the route-weighted index since 1982.

+23%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 →
45YearsYears 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 14% by 2030 — from 8.7 in 2025 to a central estimate of 10.0 (95% range 4.2–16). A 5-year backtest shows a typical error of ±34.8%, with 100% of held-out values landing inside the 95% band.

+14%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 →
10.0Projected 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 →
4.2–1695% 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 →
±34.8%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, Ruby-crowned Kinglet in BCR 4 is projected to rise about 14% by 2030 — from 8.7 in 2025 to a central estimate of 10.0 (95% range 4.2–16). A 5-year backtest shows a typical error of ±34.8%, 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 →
20269.94.216
20279.94.216
20289.94.216
20299.94.216
203010.04.216

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 →
Lake LouiseALASKA422025
SourdoughALASKA332025
HomerALASKA281982
Skilak LakeALASKA231985
Chena Hot Spring 2ALASKA202025
Ft. RichrdsnALASKA202023
Kanuti LakeALASKA202024
Goose BayALASKA171982
L SalchaALASKA162025
Koyukuk Riv.ALASKA162001
Tower BluffsALASKA142025
SavageALASKA142025
Swan Lake RdALASKA142025
ChistochinaALASKA132025
TatalinaALASKA132019
Birch LakeALASKA122025
PetersvilleALASKA122025
Chatanika RALASKA112025
KalifonskyALASKA112025
NorthwayALASKA102025
WillowALASKA102024
ChickenALASKA102025
EagleALASKA92025
CircleALASKA92025
SlanaALASKA82022

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