What year did the kiwi become extinct?

Kiwi are not extinct.

There are five species of kiwis (some sources say seven), and their conservation status varies.

The Okarito Kiwi, or Rowi (Apteryx rowi) is critically endangered.

The brown kiwi (Apteryx mantelli) is endangered.

The little spotted kiwi (Apteryx owenii), great spotted kiwi (Apteryx haastii) and tokoeka (Apteryx australis) are classified as vulnerable.