Beyond Rare: Documenting Albino-like Phenotypes as a Recurring Trait in the Juan Fernandez Fur Seal

Atypical colouration in wild animals is often considered a rare phenomenon, but its apparent rarity may partly reflect how difficult these individuals are to detect and document. This is particularly true for marine mammals, whose aquatic lifestyle can limit observation opportunities and make unusual phenotypes easy to miss. In colonial breeding otariids, however, the breeding season provides a rare opportunity to observe large numbers of individuals on land, where conspicuously coloured animals may stand out from the rest of the colony. For species that have experienced major population disturbances, recording these observations is especially relevant, as recurrent atypical phenotypes may provide useful clues about population history, persistence, and possible biological consequences.