endemic to a single state or province

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (<100-250 square km (less than about 40-100 square miles)) Known to exist only on Attu Is. Formerly, range included the other islands of the Near Islands, but has been extirpated from Agattu, Nizki/Alaid, and Shemya, assuming it occurred at the latter two locations (U88FWS03AKUS).

Comments: Nests in well drained habitat, hummocky arctic/alpine tundra with rocky ridges or outcrops and mixed vegetation (DRYAS-lichen ridges, solifluction zones, sedge meadows, SALEX or BETULA communities) (J93HOL01AKUS).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 1 - 5

Comments: One island, Attu Is., is believed to comprise the global EO for this subspecies.

2500 - 10,000 individuals

Comments: About 4,600 individuals are thought to inhabit Attu Island(B88FWS01AKUS).

United States

Rounded National Status Rank: N2 - Imperiled

Rounded Global Status Rank: T2 - Imperiled

Reasons: Highly restricted subspecies distribution. Subspecies is believed to be presently restricted to Attu Island.

Other Considerations: Ptarmigan species are known to experience large unexplained population fluctuations.

Degree of Threat: B : Moderately threatened throughout its range, communities provide natural resources that when exploited alter the composition and structure of the community over the long-term, but are apparently recoverable

Comments: Threatened at present by continued Arctic Fox presence on Attu Island.

Biological Research Needs: Research needs include: 1. Completion of DNA taxonomic determination of subspecies groups in the Aleutian Islands. 2. Population abundance and trend. 3. Population reproduction data and the influence of fox predation on population productivity and recruitment.

Global Protection: Few (1-3) occurrences appropriately protected and managed

Comments: Protection afforded by USFWS, Attu Island is part of the Alaska Maritime National Wildlife Refuge (B88FWS01AKUS).

Needs: Eliminate introduced alien predators from Near Island group in the Aleutian Islands.