1 Dollar - Elizabeth II 4th Portrait, Apteryx Rowi Kiwi, colored

New Zealand Post — the country's postal service, not the Reserve Bank — holds the license to issue commemorative legal tender coins for New Zealand, a quirk of the national mint arrangement that produces a steady stream of collector-targeted releases like this one. The Ōkārito kiwi, Apteryx rowi, was only formally recognized as a distinct species in 2003 and remains one of the rarest birds on Earth, with wild population estimates hovering below 500 individuals concentrated almost entirely on the South Island's West Coast.

The coloring on these issues is applied enamel over the struck surface — a process that makes them essentially impossible to circulate without damage, which suits their purpose entirely.