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Species · Alaska · BBS 2025 Release · 1966–2024

Pigeon Guillemot Population Trend in Alaska

All statesGeneralists

Pigeon Guillemot in Alaska has declined: down 49% on the route-weighted index since 1985.

-49%Since 1985TrendPercent 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 →
40YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Pigeon Guillemot 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 →

No notable trend signals for Pigeon Guillemot in Alaska. See the full index history below.

Pigeon Guillemot Population Forecast in Alaska

If the recent trend holds, Pigeon Guillemot in Alaska is projected to fall about 32% by 2029 — from 0.12 in 2024 to a central estimate of 0.08 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±66%, with 100% of held-out values landing inside the 95% band.

-32%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 →
0.08Projected 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 →
0.00–0.4095% 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 →
±66%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, Pigeon Guillemot in Alaska is projected to fall about 32% by 2029 — from 0.12 in 2024 to a central estimate of 0.08 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±66%, with 100% of held-out values landing inside the 95% band.19832029
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 →
20250.110.000.43
20260.100.000.42
20270.090.000.41
20280.090.000.41
20290.080.000.40

Pigeon Guillemot Survey Routes in Alaska

Routes recording Pigeon Guillemot 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 →
Yakutat420232002
Zimovia Strt320241996
Kodiak 2320241985
Cold Bay (Short)319911991
Juneau Alt219861984
Adak220011983
Cold Bay220072005
Chiniak120241985
Zarembo120172017
Juneau120131985
Ketchikan120182017
Haines120241989

Pigeon Guillemot Population Trend in Other States

californiaoregonwashington

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