Plural form of alca, a genus of seabirds including the great auk (now extinct).
From Late Latin alca, possibly of Scandinavian origin, referring to diving seabirds that were well-known in northern waters and fisheries.
The word 'alcae' is haunting because the great auk—once so numerous that sealers hunted them to complete extinction by 1844—is now only remembered through scientific Latin names like this one.
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