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GAP Analysis Predicted Distribution Map

Cassin's Auklet (Ptychoramphus aleuticus)

Species Code: PTAL

Click to enlarge Range map

= Core Habitat
= Marginal Habitat

Breeding Range Map
The green area shows the predicted habitats for breeding only. The habitats were identified using 1991 satellite imagery, Breeding Bird Atlas (BBA), other datasets and experts throughout the state, as part of the Washington Gap Analysis Project. Habitats used during non-breeding months and migratory rest-stops were not mapped.

Metadata (Data about data or how the map was made)

Click to enlarge distribution map

Other maps & Information:
  • Breeding Bird Atlas
  • NatureMapping observations
    during breeding season
  • NatureMapping observations
    throughout the year

This species is locally abundant at major nesting sites on the outer coast, on rocky islands.

Good habitat in the core areas of use included coastal shrub habitat and cliffs in the Sitka Spruce zone, limited to the islands (Mid Bodelteh I., East Bodelteh I., Carroll I., Jagged I., Dhuoyautzachtahl, and Alexander I.).

Washington breeders represent the nominate northern form P. a. aleutica. Data are scarce from the BBA period for colonial nesting seabirds due to the logistical problems of censusing offshore islands, so we relied primarily on previous data for this species. CassinŐs Auklets are the most abundant non-larid (e.g., not a gull) breeding seabird in Washington, constituting 34% of all breeding seabirds, though they occur on only six islands. Their numbers fluctuate annually, based on food supply and climatic events. El Nino/Southern Oscillation events tend to decrease seabird breeding productivity. Birds are occasionally noted in the inland waters of Puget Sound during the breeding season, but surely represent non-breeding birds.

Translated from the Washington Gap Analysis Bird Volume by Uchenna Bright
Text edited by Gussie Litwer
Webpage designed by Dave Lester