BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Arctic Tern In BCR 4

All regionsBCR 4Wetland birds

Arctic Tern in BCR 4 has collapsed: down 84% on the route-weighted index since 1978.

-84%Since 1978
41Routes In Region
45Years

Notable Signals

long arc declinecomputed index

Arctic Tern has collapsed in BCR 4: down 84% on the route-weighted index since 1978.

Forecast

If the recent trend holds, Arctic Tern in BCR 4 is projected to rise about 768% by 2029 — from 0.06 in 2024 to a central estimate of 0.49 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±1187.3%, with 100% of held-out values landing inside the 95% band.

+768%Change by 2029
0.49Projected 2029 index
0.00–1.995% range
±1187.3%Backtest error
19762029
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
20250.540.002.0
20260.530.002.0
20270.520.002.0
20280.500.002.0
20290.490.001.9

Routes In BCR 4

Routes recording Arctic Tern in BCR 4.
Seven LakesALASKA92023
Kenny LakeALASKA61990
Porcupine R.ALASKA52002
SourdoughALASKA42017
Tangle LakesALASKA41987
Mud RiverALASKA42013
Ft. RichrdsnALASKA42022
CohoeALASKA32018
Unalakleet RiverALASKA32017
ChistochinaALASKA21995
NorthwayALASKA22008
MaclarenALASKA22024
ToklatALASKA21999
HomerALASKA21978
KalifonskyALASKA22023
WillowALASKA21999
Bear CreekALASKA21991
Swan Lake RdALASKA22013
Lake LouiseALASKA22011
WasillaALASKA21983
Nicholai SlALASKA22002
PetersvilleALASKA22019
KachemakALASKA22006
Burma RoadALASKA22004
Hather CreekALASKA22017

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