Wikipedia
Aethia
Aethia is a genus of four small (85-300g) auklets endemic to the North Pacific Ocean, Bering Sea and Sea of Okhotsk and among some of North America's most abundant seabirds. The relationships between the four true auklets remains unclear. Auklets are threatened by invasive species such as Arctic foxes (Alopex lagopus) and Norway rats (Rattus norvegicus) because of their high degree of coloniality and crevice-nesting.