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Species · Alaska · BBS 2025 Release · 1966–2024

Gyrfalcon Population Trend in Alaska

All statesGeneralists

Gyrfalcon in Alaska has fallen sharply: down 57% on the route-weighted index since 1994.

-57%Since 1994TrendPercent 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 →
12Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Gyrfalcon 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 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 →

Gyrfalcon has fallen sharply in Alaska: down 57% on the route-weighted index since 1994.

Gyrfalcon Population Forecast in Alaska

If the recent trend holds, Gyrfalcon in Alaska is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±51.3%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.01Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0495% 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 →
±51.3%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, Gyrfalcon in Alaska is projected to stay roughly flat through 2027, near 0.01 (95% range 0.00–0.04). A 5-year backtest shows a typical error of ±51.3%, with 80% of held-out values landing inside the 95% band.19832027
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 →
20230.010.000.04
20240.010.000.04
20250.010.000.04
20260.010.000.04
20270.010.000.04

Gyrfalcon Survey Routes in Alaska

Routes recording Gyrfalcon 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 →
Salmon Lake220121996
Council220152003
Cold Bay220191994
Nome120071993
Nabesna Road120072007
Northway120162016
Teller120061995
Cantwell120142014
Toklat119971983
Galbraith L.120222022
Happy Valley120191993
Kanektok Riv119951995

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