BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Short-billed Gull Population Analysis

LaridaeWetland birdsLarus brachyrhynchus

Short-billed Gull has surged: up 673% on the route-weighted index since 1976.

+673%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 →
112RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
48Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Short-billed Gull

The Short-billed Gull (Larus brachyrhynchus) is a North American member of the Gulls, Terns & Skimmers (Laridae). In this analysis it is grouped with the wetland birds.

Size
8.5–31.5 in long (22–80 cm) — a long-winged waterbird (typical for the family)
Habitat
Marshes, ponds, lakeshores and other freshwater wetlands.
Diet
Aquatic invertebrates, small fish, frogs and plant matter.
Range
Recorded on 112 Breeding Bird Survey routes across 1 state, most concentrated in the BCR 4.
Family
Laridae · Wetland birds

Notable Short-billed Gull TrendsNotable 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 Short-billed Gull. See the full index history below.

Short-billed Gull Population Forecast

If the recent trend holds, Short-billed Gull is projected to rise about 73% by 2030 — from 0.07 in 2025 to a central estimate of 0.12 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±116%, with 100% of held-out values landing inside the 95% band.

+73%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 →
0.12Projected 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 →
0.00–0.2595% 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 →
±116%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, Short-billed Gull is projected to rise about 73% by 2030 — from 0.07 in 2025 to a central estimate of 0.12 (95% range 0.00–0.25). A 5-year backtest shows a typical error of ±116%, with 100% of held-out values landing inside the 95% band.19722030
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 →
20260.120.000.25
20270.120.000.25
20280.120.000.25
20290.120.000.25
20300.120.000.25

Where the Short-billed Gull Is Detected

BBS routes recording Short-billed Gull, sized by most recent count.

Short-billed Gull Population Trend by State

Short-billed Gull population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alaska-56%1976112

Short-billed Gull Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Short-billed Gull population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
BCR 2-64%198523
BCR 3-92%19953
BCR 4-40%197758
Northern Pacific Rainforest-27%198228

Short-billed Gull Conservation Status

Our route-weighted index shows it up about 673% since 1976.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.