Genus Turnagra

New Zealand Thrush - Two subspecies are recognized, the nominate T. c. capensis from the South Island mainland, and the much smaller Stephens Island Piopio from Stephens Island, which is often considered to be based on juvenile birds, but seems to be valid . The assumption of the well-flying bird evolving into a distinct subspecies on the small island close to the mainland seems hard to believe, but Stephens Island must have held a population of many hundred birds in 1894 , and the Piopio was apparently a reluctant flyer, not usually being found on offshore islands.

Turnagra tanagra - For many years, the North Island Piopio was considered to be conspecific with the South Island Piopio, but the two are now regarded as two separate species due to their pronounced differences in external appearance and apparently also osteology .