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

Franklin's Gull In Northern Rockies

All regionsNorthern RockiesWetland birds

Franklin's Gull in Northern Rockies has surged: up 279% on the route-weighted index since 1974.

+279%Since 1974
21Routes In Region
40Years

Notable Signals

long arc increasecomputed index

Franklin's Gull has surged in Northern Rockies: up 279% on the route-weighted index since 1974.

Forecast

If the recent trend holds, Franklin's Gull in Northern Rockies is projected to stay roughly flat through 2029, near 1.8 (95% range 0.00–11). A 5-year backtest shows a typical error of ±3345.6%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2029
1.8Projected 2029 index
0.00–1195% range
±3345.6%Backtest error
19702029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20251.90.0011
20261.90.0011
20271.90.0011
20281.90.0011
20291.80.0011

Routes In Northern Rockies

Routes recording Franklin's Gull in Northern Rockies.
Rock RiverWYOMING1291998
LimaMONTANA572004
WilsonWYOMING411994
Saleratus CrUTAH392007
BoulderMONTANA301993
Wolf CreekMONTANA152018
AugustaMONTANA32012
GreenoughMONTANA32003
YellowstoneWYOMING31987
FeathervilleIDAHO22013
BeaverheadMONTANA22015
Red RockMONTANA22024
Crawford MtsUTAH22002
FontenelleWYOMING22022
St MaryMONTANA11974
RandolphUTAH12021
Neponset ResUTAH12003
WoodruffUTAH12024
CodyWYOMING12001
ClarkWYOMING12000
AlpineWYOMING12016

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