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Species · BCR 4 · BBS 2026 Release · 1966–2025

Herring Gull In BCR 4

All regionsBCR 4Wetland birds

Herring Gull in BCR 4 has held roughly steady: down 2% on the route-weighted index since 1976.

-2%Since 1976TrendPercent 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 →
43Routes 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 →
46YearsYears 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 →

No notable trend signals for Herring Gull in BCR 4. See the full index history below.

Herring Gull In BCR 4 Population Forecast

If the recent trend holds, Herring Gull in BCR 4 is projected to rise about 252% by 2030 — from 1.2 in 2025 to a central estimate of 4.2 (95% range 0.00–12). A 5-year backtest shows a typical error of ±244.4%, with 80% of held-out values landing inside the 95% band.

+252%Change by 2030TrendPercent 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 →
4.2Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1295% 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 →
±244.4%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, Herring Gull in BCR 4 is projected to rise about 252% by 2030 — from 1.2 in 2025 to a central estimate of 4.2 (95% range 0.00–12). A 5-year backtest shows a typical error of ±244.4%, with 80% of held-out values landing inside the 95% band.19682030
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 →
20264.00.0012
20274.00.0012
20284.10.0012
20294.10.0012
20304.20.0012

Routes In BCR 4

Routes recording Herring Gull in BCR 4.
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 →
KalifonskyALASKA3222023
Kenny LakeALASKA352025
CohoeALASKA212023
ChistochinaALASKA132024
KuskulanaALASKA82025
TonsinaALASKA62016
Nicholai SlALASKA62018
Porcupine R.ALASKA52002
DeltaALASKA42024
NorthwayALASKA32022
Goose BayALASKA31982
Lake LouiseALASKA32012
KachemakALASKA32024
Unalakleet RiverALASKA31999
MonahanALASKA22021
SavageALASKA22016
WasillaALASKA21983
McgrathALASKA22019
TatalinaALASKA22012
Kanuti LakeALASKA22022
Birch LakeALASKA12024
SlanaALASKA12024
MaclarenALASKA12025
CantwellALASKA11982
Skilak LakeALASKA11984

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.