BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Glaucous-winged Gull In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestWetland birds

Glaucous-winged Gull in Northern Pacific Rainforest has fallen sharply: down 53% on the route-weighted index since 1970.

-53%Since 1970TrendPercent 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 →
53Routes 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 →
56YearsYears 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 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 →

Glaucous-winged Gull has fallen sharply in Northern Pacific Rainforest: down 53% on the route-weighted index since 1970.

Glaucous-winged Gull In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Glaucous-winged Gull in Northern Pacific Rainforest is projected to rise about 30% by 2029 — from 2.3 in 2024 to a central estimate of 2.9 (95% range 0.00–8.9). A 5-year backtest shows a typical error of ±136.8%, with 100% of held-out values landing inside the 95% band.

+30%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 →
2.9Projected 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 →
0.00–8.995% 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 →
±136.8%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-winged Gull in Northern Pacific Rainforest is projected to rise about 30% by 2029 — from 2.3 in 2024 to a central estimate of 2.9 (95% range 0.00–8.9). A 5-year backtest shows a typical error of ±136.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.10.009.1
20263.00.009.0
20273.00.009.0
20283.00.009.0
20292.90.008.9

Routes In Northern Pacific Rainforest

Routes recording Glaucous-winged Gull in Northern Pacific Rainforest.
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 →
Port AngelesWASHINGTON622024
CordovaALASKA212024
YakutatALASKA212024
JuneauALASKA162024
Warm Beach 2WASHINGTON142021
Mitkof IsleALASKA122010
Zimovia StrtALASKA122024
TaholahWASHINGTON122022
SitkaALASKA112024
Warm BeachWASHINGTON112017
MukilteoWASHINGTON112024
SkagwayALASKA102024
NavarroCALIFORNIA101995
SewardALASKA71984
KetchikanALASKA72019
GlasgowOREGON72015
Bay ViewWASHINGTON62017
HainesALASKA42022
Juneau AltALASKA31986
CraigALASKA31991
Copper RiverALASKA32011
Crescent CtyCALIFORNIA32001
IlwacoWASHINGTON32022
Thompson PasALASKA22002
HoonahALASKA22022

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