BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

California Gull In Badlands and Prairies

All regionsBadlands and PrairiesWetland birds

California Gull in Badlands and Prairies has declined: down 49% on the route-weighted index since 1971.

-49%Since 1971TrendPercent 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 →
24Routes 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 →
49YearsYears 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 Badlands and Prairies. See the full index history below.

Forecast

If the recent trend holds, California Gull in Badlands and Prairies is projected to stay roughly flat through 2029, near 0.19 (95% range 0.00–0.74). A 5-year backtest shows a typical error of ±350.3%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.19Projected 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 →
0.00–0.7495% 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 →
±350.3%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 Badlands and Prairies is projected to stay roughly flat through 2029, near 0.19 (95% range 0.00–0.74). A 5-year backtest shows a typical error of ±350.3%, 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 →
20250.190.000.74
20260.190.000.74
20270.190.000.74
20280.190.000.74
20290.190.000.74

Routes In Badlands and Prairies

Routes recording California Gull in Badlands and Prairies.
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 →
JordanMONTANA112012
IngomarMONTANA101990
Flatwillow 2MONTANA102022
NatronaWYOMING71992
DwyerWYOMING62019
BucknumWYOMING62000
TobaccoNORTH-DAKOTA52006
FlatwillowMONTANA41999
Teapot DomeWYOMING41983
BrusettMONTANA22017
CircleMONTANA22018
Two DotMONTANA22024
UptonWYOMING22022
HighwoodMONTANA12023
LeroyMONTANA12009
RoyMONTANA12017
ShawmutMONTANA12001
Reed PointMONTANA11991
WinnettMONTANA12021
Dunn CenterNORTH-DAKOTA12018
Fort PierreSOUTH-DAKOTA12024
WelchWYOMING12007
RozetWYOMING12023
Gvnt ValleyWYOMING12005

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