The Cassin’s Auklet is a small seabird with steel-gray coloring on its back and a white belly. It has a white stripe near the eye and a pale, whitish iris. Its coloring helps it blend in with the ocean, making it hard to spot at sea.
Cassin’s Auklet is one of the most widespread alcid species in the Pacific Ocean, though only a few nest in Oregon. They nest on islands and rocky coastlines, using shallow burrows or cracks in rocks to lay their eggs.
When not breeding, Cassin’s Auklets stay far offshore, beyond the continental shelf, in the eastern Pacific Ocean.
Cassin’s Auklets require deep soils or crevices for burrowing and nesting on offshore islands that lack mammalian predators. They are vulnerable to aerial predators, especially large gulls and falcons. Individuals typically fly between the sea and their colonies at night.
Limiting factors
Marine forage availability in proximity to nesting islands can be limiting, and variable marine conditions affect prey availability. Periodic large-scale algal blooms may disrupt food availability. Cassin’s Auklets are vulnerable to predation by mammals on nesting islands, oil spills, impacts of marine development and marine plastic pollution. Additionally, they are susceptible to direct impacts from fisheries as bycatch.
Data gaps
• Collect population size and demographic data. Breeding islands are difficult to access and very few occurrence records exist.
• Describe Oregon-specific threats to the population
Conservation actions
• Develop appropriate survey methodology for populations and habitat.
• Monitor islands for mammalian predator issues.
• Investigate the role of variable prey availability and ocean current changes on survival and recruitment.
Key reference or plan
Pacific Region Seabird Conservation Plan. Read here
The Coastal Observation and Seabird Survey Team (COASST). Read here
