The black robin or Chatham Island robin (Petroica traversi) is an endangered bird from the Chatham Islands off the east coast of New Zealand. It is closely related to the South Island robin (P. australis). It was first described by Walter Buller in 1872. Unlike its mainland counterparts, its flight capacity is somewhat reduced. Evolution in the absence of mammalian predators made it vulnerable to introduced species such as cats and rats, and it became extinct on the main island of the Chatham group before 1871, being restricted to Little Mangere Island thereafter.