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Species · Alaska · BBS 2025 Release · 1966–2024

Yellow-bellied Flycatcher Population Trend in Alaska

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Yellow-bellied Flycatcher in Alaska has surged: up 15× on the route-weighted index since 1995.

15×Since 1995TrendPercent 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 →
15Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
29YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-bellied Flycatcher Trends in AlaskaNotable 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 →

Yellow-bellied Flycatcher has surged in Alaska: up 15× on the route-weighted index since 1995.

Yellow-bellied Flycatcher Population Forecast in Alaska

If the recent trend holds, Yellow-bellied Flycatcher in Alaska is projected to fall about 10% by 2029 — from 0.45 in 2024 to a central estimate of 0.40 (95% range 0.27–0.53). A 5-year backtest shows a typical error of ±36.7%, with 20% of held-out values landing inside the 95% band.

-10%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 →
0.40Projected 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 →
0.27–0.5395% 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 →
±36.7%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, Yellow-bellied Flycatcher in Alaska is projected to fall about 10% by 2029 — from 0.45 in 2024 to a central estimate of 0.40 (95% range 0.27–0.53). A 5-year backtest shows a typical error of ±36.7%, with 20% of held-out values landing inside the 95% band.19902029
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 →
20250.350.230.48
20260.370.240.50
20270.380.250.51
20280.390.260.52
20290.400.270.53

Yellow-bellied Flycatcher Survey Routes in Alaska

Routes recording Yellow-bellied Flycatcher in Alaska.
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. Fairplay1720241994
Chicken720241996
Eagle420242001
Chatanika R420232021
Birch Lake220192015
Monahan220102010
Kanuti Canyn220242008
Livengood120212015
Slana120172008
Tower Bluffs120222006
Northway120191997
Nabesna Road120142014
Juneau119901990
Sourdough119951994
Kanuti Lake120132013

Yellow-bellied Flycatcher Population Trend in Other States

mainemassachusettsmichiganminnesotanew-hampshirenew-yorkpennsylvaniavermontwisconsin

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