New Zealand sea lion
The New Zealand sea lion (Phocarctos hookeri), once known as Hooker's sea lion, and as pakake or whakahao (male) and kaki (female) in Māori,[2] is a species of sea lion that is endemic to New Zealand and primarily breeds on New Zealand's subantarctic Auckland and Campbell islands, and have in recent years been slowly breeding and recolonising around the coast of New Zealand's South and Stewart islands.[3] The New Zealand sea lion numbers around 12,000 and is one of the world's rarest sea lion species.[4] They are the only species of the genus Phocarctos.
New Zealand sea lions are one of the largest New Zealand animals. Like all otariids, they have marked sexual dimorphism; adult males are 240–350 centimetres (7.9–11.5 ft) long and weigh 320–450 kilograms (710–990 lb), while adult females are 180–200 centimetres (5.9–6.6 ft) long and weigh 90–160 kilograms (200–350 lb).[5] At birth, pups are 70–100 centimetres (2.3–3.3 ft) long and weigh 8–10 kilograms (18–22 lb); the natal pelage is a thick coat of dark brown hair that becomes dark gray with cream markings on the top of the head, nose, tail and at the base of the flippers. Adult females' coats vary from buff to creamy grey with darker pigmentation around the muzzle and the flippers. Adult males are blackish-brown with a well-developed black mane of coarse hair reaching the shoulders.[6] New Zealand sea lions are strongly philopatric.[7]
The New Zealand sea lion's terrestrial behaviour is unique among other pinniped species. In the breeding season, female New Zealand sea lions gradually move inland with their pups to protect them from harassment by males, wind, storms, and potential parasitic infections.[8] They can move up to 2 kilometres (1.2 mi) inland, from sandy beaches to tall grasses, and into forests.[9][10] They are the only pinniped species known to disperse far inland and have a preference for forests.[8]
The main breeding populations are at the Auckland and Campbell Islands in the New Zealand subantarctic, where approximately 99% of the species' annual pup production occurs. There are currently three functioning breeding rookeries on the Auckland Islands.[11] Most sea lions are born on Dundas Island. A smaller rookery exists at Sandy Bay on Enderby Island and the smallest rookery is on Figure of Eight Island. An even smaller rookery at South East Point on Auckland Island appears to now have been abandoned. The other major breeding area is the Campbell Islands.
Historically, New Zealand sea lions were distributed all over mainland New Zealand and Stewart Island, but were extirpated from these areas due to human hunting activities.[12][13] For the first time in over 150 years, sea lions began breeding again on the South Island coast in 1993, on the Otago Peninsula.[12] Other small populations of breeding sea lions have recently begun to establish in various parts of the Stewart Island coastline and have been observed on the Catlins coast south of the Clutha River.[14]
Recent DNA information indicates the New Zealand sea lion is a lineage previously restricted to subantarctic regions. Somewhere between 1300 and 1500 AD, a genetically distinct mainland lineage was wiped out by the first Maori settlers,[15] and the subantarctic lineage has since then gradually filled the ecological niche.[16] It has been inferred from middens and ancient DNA that a third lineage was made extinct at the Chatham Islands due to predation by the Moriori people.[17][18]
