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Species · Montana · BBS 2026 Release · 1966–2025

Franklin's Gull Population Trend in Montana

All statesWetland birds

Franklin's Gull in Montana has surged: up 242% on the route-weighted index since 1970.

+242%Since 1970TrendPercent 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 →
33Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Franklin's Gull Trends in MontanaNotable 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 →

Franklin's Gull has surged in Montana: up 242% on the route-weighted index since 1970.

Franklin's Gull Population Forecast in Montana

If the recent trend holds, Franklin's Gull in Montana is projected to fall about 18% by 2030 — from 9.4 in 2025 to a central estimate of 7.7 (95% range 0.00–24). A 5-year backtest shows a typical error of ±82.5%, with 80% of held-out values landing inside the 95% band.

-18%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 →
7.7Projected 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 →
0.00–2495% 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 →
±82.5%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, Franklin's Gull in Montana is projected to fall about 18% by 2030 — from 9.4 in 2025 to a central estimate of 7.7 (95% range 0.00–24). A 5-year backtest shows a typical error of ±82.5%, 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 →
20267.50.0024
20277.60.0024
20287.60.0024
20297.70.0024
20307.70.0024

Franklin's Gull Survey Routes in Montana

Routes recording Franklin's Gull in Montana.
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 →
Chinook50120252015
Virgelle21720251979
Malta8020211975
Lima5720041999
Great Falls3720241972
Cleveland3520252024
Boulder3019931970
Sun River2020252016
Harlem1820171968
Hay Lake1720172003
Wolf Creek1520182018
Roundup620242024
Wheat Basin620232023
Gildford520242017
Greenough320032003
Augusta320122012
Circle319931993
Sunburst219981968
Leroy220242024
Beaverhead220151981
Red Rock220241980
Ester Lake220252016
St Mary119741972
Glasgow120251969
Redstone120192004

Franklin's Gull Population Trend in Other States

californiacoloradoidahokansasminnesotanebraskanorth-dakotaoregonsouth-dakotautahwyoming

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