Observations of Leucistic ʻUaʻu (Hawaiian Petrel Pterodroma sandwichensis) on Lānaʻi, Hawaiʻi

The ‘Ua‘u (Hawaiian Petrel Pterodroma sandwichensis) is an endangered petrel endemic to the Hawaiian Islands. In this short paper, we describe two cases of Hawaiian Petrels with leucistic plumage recorded on the island of La¯na‘i. In both cases, the birds were chicks that fledged successfully in different years from the same burrow. There is only one other documented case of leucism recorded for this species in the Hawaiian Islands despite intensive monitoring of petrel burrows on Kaua‘i, La¯na‘i, and Maui over the last few decades, highlighting the rarity of this plumage aberration.