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Species · Montana · BBS 2025 Release · 1966–2024

Franklin's Gull Population Trend in Montana

All statesWetland birds

Franklin's Gull in Montana has surged: up 184% on the route-weighted index since 1970.

+184%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 →
52YearsYears 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 183% 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 stay roughly flat through 2029, near 7.5 (95% range 0.00–24). A 5-year backtest shows a typical error of ±104.2%, with 80% of held-out values landing inside the 95% band.

-8%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 →
7.5Projected 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 →
0.00–2495% 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 →
±104.2%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 stay roughly flat through 2029, near 7.5 (95% range 0.00–24). A 5-year backtest shows a typical error of ±104.2%, with 80% 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 →
20257.40.0024
20267.40.0024
20277.40.0024
20287.50.0024
20297.50.0024

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 →
Highwood90020161968
Virgelle36920241979
Ester Lake12820242016
Sun River10220242016
Malta8020211975
Lima5720041999
Great Falls3720241972
Boulder3019931970
Chinook2120242015
Glasgow2020241969
Harlem1820171968
Hay Lake1720172003
Wolf Creek1520182018
Roundup620242024
Wheat Basin620232023
Gildford520242017
Cleveland320242024
Greenough320032003
Augusta320122012
Circle319931993
Sunburst219981968
Leroy220242024
Beaverhead220151981
Red Rock220241980
St Mary119741972

Franklin's Gull Population Trend in Other States

californiaidahokansasminnesotanebraskanorth-dakotaoregonsouth-dakotautahwyoming

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