The New Zealand sea lion, also known as Hooker's sea lion (Phocarctos hookeri), is one of the rarest and most threatened sea lions in the world. Adult males are dark blackish-brown in colour and have a distinct light mane that reaches down to their shoulders. Females are grey or buff-coloured, and have a paler belly. Males are much larger than females. Pups are born with a thick covering of dark hair, which is lost at some point after birth.