BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

Glaucous Gull In BCR 2

All regionsBCR 2Wetland birds

Glaucous Gull in BCR 2 has surged: up 448% on the route-weighted index since 1993.

+448%Since 1993TrendPercent 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 →
13Routes 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 →
33YearsYears 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 →

Glaucous Gull has surged in BCR 2: up 448% on the route-weighted index since 1993.

Forecast

If the recent trend holds, Glaucous Gull in BCR 2 is projected to rise about 444% by 2029 — from 9.0 in 2024 to a central estimate of 49 (95% range 4.1–94). A 5-year backtest shows a typical error of ±282.1%, with 60% of held-out values landing inside the 95% band.

+444%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 →
49Projected 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 →
4.1–9495% 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 →
±282.1%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, Glaucous Gull in BCR 2 is projected to rise about 444% by 2029 — from 9.0 in 2024 to a central estimate of 49 (95% range 4.1–94). A 5-year backtest shows a typical error of ±282.1%, with 60% of held-out values landing inside the 95% band.19862029
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 →
2025450.4890
2026461.491
2027472.392
2028483.293
2029494.194

Routes In BCR 2

Routes recording Glaucous Gull in BCR 2.
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 →
Kotzebue (Short)ALASKA1681994
KotzebueALASKA802024
CouncilALASKA82018
TupuknukALASKA61995
NomeALASKA52023
St. Mary'SALASKA52011
Kugarak (Short)ALASKA51987
Gweek RiverALASKA22002
Selawik (Short)ALASKA21987
ChiniakALASKA12015
Cape NomeALASKA12024
Salmon LakeALASKA12018
TellerALASKA12009

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