BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Ring-billed Gull In Northern Rockies

All regionsNorthern RockiesWetland birds

Ring-billed Gull in Northern Rockies has surged: up 894% on the route-weighted index since 1971.

+894%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 →
52Routes 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 →
54YearsYears 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 increasecomputed 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 →

Ring-billed Gull has surged in Northern Rockies: up 894% on the route-weighted index since 1971.

Forecast

If the recent trend holds, Ring-billed Gull in Northern Rockies is projected to rise about 90% by 2029 — from 1.5 in 2024 to a central estimate of 2.8 (95% range 0.00–6.7). A 5-year backtest shows a typical error of ±225.3%, with 100% of held-out values landing inside the 95% band.

+90%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 →
2.8Projected 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 →
0.00–6.795% 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 →
±225.3%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, Ring-billed Gull in Northern Rockies is projected to rise about 90% by 2029 — from 1.5 in 2024 to a central estimate of 2.8 (95% range 0.00–6.7). A 5-year backtest shows a typical error of ±225.3%, 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 →
20252.70.006.6
20262.70.006.6
20272.80.006.7
20282.80.006.7
20292.80.006.7

Routes In Northern Rockies

Routes recording Ring-billed Gull in Northern Rockies.
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 →
Neponset ResUTAH2502018
AugustaMONTANA1282024
Pablo Res.MONTANA472024
CabartonIDAHO291986
MidvaleWYOMING292022
RawlinsWYOMING141999
RandolphUTAH132024
HarmonyWYOMING122022
Willow Creek 2MONTANA112014
Mtn ViewWYOMING101980
Saleratus CrUTAH92017
Green RiverWYOMING91982
Carter 2WYOMING92021
FontenelleWYOMING82024
BoulderMONTANA72022
CascadeIDAHO61976
BeaverheadMONTANA52019
Heart ButteMONTANA52024
CumberlandWYOMING51979
MckinnonWYOMING51983
E. Bear LakeUTAH42021
FeathervilleIDAHO32022
Flamin GorgeWYOMING32024
Crane CreekIDAHO22015
KalispellMONTANA22024

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