BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Franklin's Gull In Great Basin

All regionsGreat BasinWetland birds

Franklin's Gull in Great Basin has increased: up 34% on the route-weighted index since 1972.

+34%Since 1972TrendPercent 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 →
40Routes 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 →
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 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 Franklin's Gull in Great Basin. See the full index history below.

Franklin's Gull In Great Basin Population Forecast

If the recent trend holds, Franklin's Gull in Great Basin is projected to rise about 12× by 2030 — from 0.57 in 2025 to a central estimate of 6.9 (95% range 0.00–14). A 5-year backtest shows a typical error of ±223.9%, with 100% of held-out values landing inside the 95% band.

12×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 →
6.9Projected 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 →
0.00–1495% 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 →
±223.9%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 Great Basin is projected to rise about 12× by 2030 — from 0.57 in 2025 to a central estimate of 6.9 (95% range 0.00–14). A 5-year backtest shows a typical error of ±223.9%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20266.70.0014
20276.70.0014
20286.80.0014
20296.90.0014
20306.90.0014

Routes In Great Basin

Routes recording Franklin's Gull in Great Basin.
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 →
PromontoryUTAH7412024
PrestonIDAHO3782023
HenryIDAHO1161981
Blacks CreekIDAHO942015
Harney LakeOREGON752022
Cedar HillIDAHO612015
DeltaUTAH432004
RirieIDAHO402019
Bear RiverUTAH362025
Tractor FlatIDAHO342025
Malheur NwrOREGON322022
Johnson CanUTAH301992
Modoc PointOREGON132009
PrincetonOREGON131985
Mud LakeIDAHO112023
LakeviewOREGON112022
BakerIDAHO71984
PocatelloIDAHO62015
Warner VallyOREGON52023
Pasadena ValIDAHO41993
Fish LakeOREGON32025
Catlow RimOREGON32024
ChinchaloOREGON32016
SpringfieldIDAHO22018
Daniels ResIDAHO22017

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