BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Forster's Tern In Great Basin

All regionsGreat BasinWetland birds

Forster's Tern in Great Basin has increased: up 31% on the route-weighted index since 1970.

+31%Since 1970
58Routes In Region
56Years

Notable Signals

No notable trend signals for Forster's Tern in Great Basin. See the full index history below.

Forecast

If the recent trend holds, Forster's Tern in Great Basin is projected to rise about 309% by 2029 — from 0.11 in 2024 to a central estimate of 0.47 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±166.7%, with 100% of held-out values landing inside the 95% band.

+309%Change by 2029
0.47Projected 2029 index
0.00–1.595% range
±166.7%Backtest error
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 index95% low95% high
20250.520.001.5
20260.510.001.5
20270.490.001.5
20280.480.001.5
20290.470.001.5

Routes In Great Basin

Routes recording Forster's Tern in Great Basin.
DorrisCALIFORNIA682019
Bear RiverUTAH352023
Fish LakeOREGON142024
PrincetonOREGON111985
Glenns FerryIDAHO101968
Lapham Res.OREGON102022
Malheur NwrOREGON101992
PrestonIDAHO92004
MacdoelCALIFORNIA72018
Blizzard GapOREGON72023
Trout CreekOREGON72000
Columbia NwrWASHINGTON62021
TriangleIDAHO52014
MerrillOREGON52013
Moses LakeWASHINGTON52021
Iron GateCALIFORNIA42002
Cedar HillIDAHO42014
Warner VallyOREGON42019
Crowder FlatCALIFORNIA32006
Bald Mtn.NEVADA32015
Modoc PointOREGON32018
LeamingtonUTAH31992
Hanford SiteWASHINGTON31996
IngallsCALIFORNIA22001
Crowley LakeCALIFORNIA21988

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