BirdAnalyst
Species · BCR 14 · BBS 2025 Release · 1966–2024

Ruby-crowned Kinglet In Atlantic Northern Forest

All regionsAtlantic Northern ForestForest birds

Ruby-crowned Kinglet in Atlantic Northern Forest has fallen sharply: down 61% on the route-weighted index since 1968.

-61%Since 1968TrendPercent 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 →
112Routes 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 →
58YearsYears 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 fallen sharply in Atlantic Northern Forest: down 61% on the route-weighted index since 1968.

Ruby-crowned Kinglet In Atlantic Northern Forest Population Forecast

If the recent trend holds, Ruby-crowned Kinglet in Atlantic Northern Forest is projected to rise about 39% by 2029 — from 0.16 in 2024 to a central estimate of 0.22 (95% range 0.00–0.85). A 5-year backtest shows a typical error of ±54.8%, with 100% of held-out values landing inside the 95% band.

+39%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 →
0.22Projected 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 →
0.00–0.8595% 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 →
±54.8%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 Atlantic Northern Forest is projected to rise about 39% by 2029 — from 0.16 in 2024 to a central estimate of 0.22 (95% range 0.00–0.85). A 5-year backtest shows a typical error of ±54.8%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.260.000.89
20260.250.000.88
20270.240.000.87
20280.230.000.86
20290.220.000.85

Routes In Atlantic Northern Forest

Routes recording Ruby-crowned Kinglet in Atlantic Northern Forest.
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 →
Big TwentyMAINE172008
Pillsbury PdMAINE111968
YankeetuladiMAINE92009
Big Twenty 2MAINE92009
Moose RiverMAINE52008
Weeks BrookMAINE52016
Lake MoxieMAINE52010
ClarksvilleNEW-HAMPSHIRE42024
Otisfield GrMAINE31975
Bowdoin CtrMAINE31975
HarmonyMAINE31996
BentonMAINE31980
NorthfieldMAINE31981
Seboomook LkMAINE32014
St DavidMAINE32005
Northfield 2MAINE31998
Dixvil NotchNEW-HAMPSHIRE32017
Dixville Notch 2NEW-HAMPSHIRE32024
NewcombNEW-YORK32013
BethelMAINE21977
GreenwoodMAINE22005
South ArmMAINE21999
HermonMAINE21992
HancockMAINE21987
AuroraMAINE21998

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