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

Willow Ptarmigan In BCR 4

All regionsBCR 4Generalists

Willow Ptarmigan in BCR 4 has fallen sharply: down 54% on the route-weighted index since 1984.

-54%Since 1984
14Routes In Region
40Years

Notable Signals

long arc declinecomputed index

Willow Ptarmigan has fallen sharply in BCR 4: down 54% on the route-weighted index since 1984.

Forecast

If the recent trend holds, Willow Ptarmigan in BCR 4 is projected to fall about 66% by 2029 — from 0.47 in 2024 to a central estimate of 0.16 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±50.9%, with 100% of held-out values landing inside the 95% band.

-66%Change by 2029
0.16Projected 2029 index
0.00–0.7895% range
±50.9%Backtest error
19822029
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
20250.200.000.82
20260.190.000.81
20270.180.000.80
20280.170.000.79
20290.160.000.78

Routes In BCR 4

Routes recording Willow Ptarmigan in BCR 4.
SavageALASKA122024
ToklatALASKA42024
Pinoche Tral (Short)ALASKA31984
MonahanALASKA22018
Caribou Mtn.ALASKA22023
EagleALASKA12022
MaclarenALASKA12024
CantwellALASKA12018
Hatcher PassALASKA12018
ColdfootALASKA12006
Donelly DomeALASKA12013
Paxson LakeALASKA11996
Nabesna RoadALASKA12016
Mccarthy Rd2ALASKA11991

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