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

Common Yellowthroat In BCR 4

All regionsBCR 4Forest birds

Common Yellowthroat in BCR 4 has surged: up 171% on the route-weighted index since 1999.

+171%Since 1999TrendPercent 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 →
8Routes 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 →
20YearsYears 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 →

Common Yellowthroat has surged in BCR 4: up 171% on the route-weighted index since 1999.

Common Yellowthroat In BCR 4 Population Forecast

If the recent trend holds, Common Yellowthroat in BCR 4 is projected to rise about 72% by 2029 — from 0.08 in 2024 to a central estimate of 0.14 (95% range 0.05–0.24). A 5-year backtest shows a typical error of ±106.9%, with 60% of held-out values landing inside the 95% band.

+72%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 →
0.14Projected 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 →
0.05–0.2495% 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 →
±106.9%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, Common Yellowthroat in BCR 4 is projected to rise about 72% by 2029 — from 0.08 in 2024 to a central estimate of 0.14 (95% range 0.05–0.24). A 5-year backtest shows a typical error of ±106.9%, with 60% of held-out values landing inside the 95% band.19932029
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 →
20250.130.040.22
20260.130.040.23
20270.140.040.23
20280.140.050.23
20290.140.050.24

Routes In BCR 4

Routes recording Common Yellowthroat 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 →
Mt. FairplayALASKA22017
EagleALASKA12024
SlanaALASKA12024
Tower BluffsALASKA12015
ChistochinaALASKA11993
NorthwayALASKA12023
CantwellALASKA12017
ChickenALASKA12024

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