Endemic to New Zealand, the variable oystercatcher (Haematopus unicolor) is named due to its inconsistent feather colour (plumage). Unlike other species, individuals can be completely black, black-and-white (pied), or a blotchy mixture in between. Early naturalists hought these different colour phases belonged to entirely separate species, but as they freely interbreed and belong to a single species, the descriptor "variable" was adopted. Known as tōrea-pango in Māori, their feather colour depends heavily on latitude. Northern birds are more likely to have white patches (pied or mottled), while 100% of the variable oystercatchers on Stewart Island in the far south are completely black.
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