BirdAnalyst
Species · BCR 18 · BBS 2026 Release · 1966–2025

California Gull In Shortgrass Prairie

All regionsShortgrass PrairieWetland birds

California Gull in Shortgrass Prairie has surged: up 13× on the route-weighted index since 1986.

13×Since 1986TrendPercent 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 →
6Routes 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 →
24YearsYears 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 California Gull in Shortgrass Prairie. See the full index history below.

California Gull In Shortgrass Prairie Population Forecast

If the recent trend holds, California Gull in Shortgrass Prairie is projected to stay roughly flat through 2030, near 0.31 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±688%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.31Projected 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 →
0.00–1.195% 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 →
±688%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, California Gull in Shortgrass Prairie is projected to stay roughly flat through 2030, near 0.31 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±688%, with 80% of held-out values landing inside the 95% band.19812030
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 →
20260.300.001.1
20270.310.001.1
20280.310.001.1
20290.310.001.1
20300.310.001.1

Routes In Shortgrass Prairie

Routes recording California Gull in Shortgrass Prairie.
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 →
BriggsdaleCOLORADO952023
Fort MorganCOLORADO42000
YoderWYOMING42012
JulesburgCOLORADO32002
HudsonCOLORADO12025
Doyle BridgeCOLORADO11994

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