The four species that inhabit sea ice are thought to make up 50% of the total biomass of the world's seals.[14] Crabeater seals have a population of around 15 million, making them one of the most numerous large animals on the planet.[15] The New Zealand sea lion (Phocarctos hookeri), one of the rarest and most localised pinnipeds, breeds almost exclusively on the subantarctic Auckland Islands, although historically it had a wider range.[16] Out of all permanent mammalian residents, the Weddell seals live the furthest south.[17]