The New Zealand sea lion (Phocarctos hookeri), previously known as the Hooker's sea lion, and called in Māori pakake or whakahao (male) and kake (female), is a large pinniped from the family Otariidae (eared seals and sea lions) endemic to New Zealand.

The New Zealand sea lion is one of the rarest otariids in the world with a total population estimate of less than 10,000 individuals and fewer than 5,000 breeding adults. This number has declined from an estimated population of over 15,000 in the early 2000s.

Description

New Zealand sea lions are sexually dimorphic – they display distinct physical differences between adult females and adult males.

Adult females have a light coloration ranging from grey to light brown, featuring a nearly white underside and dark flippers. They can reach lengths of up to 2 m and weights of up to 160 kg.

Adult males are significantly larger, measuring up to 3 m and weighing up to 450 kg. They are typically dark brown in colour and possess prominent manes that extend to their shoulders. Their coloration can vary – some may appear entirely black, while others may have a light brown to blond appearance.

Pups are born from December to mid-January. Newly born pups typically weigh about 10 kg and are approximately 80 cm in length. During the initial 4 months of their lives, pups are generally dark brown with a lighter blonde patch on the top of their heads, though some pups may be born with a light brown or blonde body colour. After around 4 months, pups moult and shed their fur. Both male and female pups then turn grey like adult females.

Most males gradually darken to brown after their first year and start developing a mane around age 4 or 5, though some young males (subadult males) continue to resemble females in body shape and colour in their third year. Males reach their full adult size with large manes at around age 8.

The New Zealand sea lion is larger than the other eared seal commonly found along the New Zealand coast, the kekeno (New Zealand fur seal, Arctocephalus forsteri). Sea lions can also be identified by their lighter colour (for females), blunter nose, and shorter whiskers.

New Zealand sea lions have a maximum lifespan of approximately 15-20 years. The oldest recorded female lived to be 28 years old, and the maximum recorded age for a male is 23 years.

Breeding

The age of sexual maturity for female New Zealand sea lions is around three years and females can give birth to one pup per year, though not all females breed every year.  Males are sexually mature at age five but most cannot hold their own territory in breeding aggregations, where most mating occurs, until age eight.

Most adult New Zealand sea lions gather in breeding aggregations each year in December. Pupping (birth of pups) begins in early December and ends by mid-January. Mating takes place during the same period, soon after pupping. Females give birth to a single pup and remain on land with their pup for approximately one week before leaving to feed at sea. The females then alternate periods on land suckling pups and periods foraging at sea. The amount of time spent on land and at sea varies greatly amongst females and between the South Island and subantarctic animals, but it is usually 1-2 days on land followed by 1-3 days at sea.

Pups born outside of the breeding aggregations are left alone on land for up to three or more days while their mothers are at sea feeding. This is a natural phenomenon, but these solitary pups are especially vulnerable to disturbance by humans and dogs.

Pups born into the breeding aggregations or to solitary females are generally moved by the females to another location, often a creching site with other females and pups, when they are about six weeks old. Breeding aggregations disperse widely by late January.

Pups are dependent on their mothers for milk for at least 10 months and females can continue nursing their pups through their second year. Rarely, some females have been recorded nursing 3-year-old juveniles.

Distribution

Approximately 93% of all New Zealand sea lion pups are born on the subantarctic islands, at the Auckland Islands and Campbell Island.

Historically, New Zealand sea lions bred in many locations around the North and South Islands, Rakiura/Stewart Island, and the Chatham Islands. But by the end of the 19th century, they had been extirpated (eliminated) from many of these areas because of subsistence and commercial hunting.

Most New Zealand sea lion pups are born into temporary breeding aggregations. Adult males and females congregate at the same sites each year during December and January. Female New Zealand sea lions show strong philopatry and almost always return to the breeding colonies where they were born to mate and give birth.

New Zealand sea lions are not migratory. Outside the breeding season they disperse from the breeding aggregations, but most remain in the same area, using a range of land sites and similar foraging areas. Juveniles of both sexes can also disperse widely, but most animals return to their place of birth to breed once they reach maturity.

Subantarctic islands

The main breeding area for the species is the subantarctic Auckland Islands, where around 70% of pups are born each year. Breeding aggregations form annually on Dundas Island (where over half of all pups are born), at Sandy Bay on Enderby Island, and on Figure of Eight Island in Carnley Harbour.

On Campbell Island, two breeding aggregations occur in Perseverance Harbour. The aggregations at Davis Point and Shoal Point (formerly Paradise Point) produce about 23% of all pups born each year.

All five subantarctic breeding aggregations, three at the Auckland Islands and two at Campbell Island,are classified as colonies, producing at least 35 pups at each site each year. The smallest of these colonies is located at Figure of Eight Island, and the largest colony is on Dundas Island.

Some adult males from the subantarctic colonies can disperse widely during the non-breeding season and have been recorded from Macquarie Island to the South Island of New Zealand.

Rakiura/Stewart Island and Te Waipounamu/the South Island

New Zealand sea lions have started recolonising their historic breeding range on Rakiura/Stewart Island and Te Waipounamu/the South Island. As of 2025, 5% of New Zealand sea lion pups were born at Rakiura and nearly 2% of pups were born on the South Island.

Small numbers of females, and later pups, were found at Port Pegasus, Rakiura during the 1990s and 2000s and DOC has conducted annual surveys of the area since 2011. The number of pups found there each year increased from 16 in 2011 to 96 by 2025. Port Pegasus was recognised as a breeding colony in 2021 after more than 35 pups were born there for five consecutive years. There is currently no breeding aggregation in Port Pegasus. Instead, females give birth to their pups along the forested coastline, individually or in small groups.

The recolonisation of mainland New Zealand has started in two areas on the South Island: Otago and the Catlins.

Male New Zealand sea lions continued to visit the Otago coastline after commercial sealing was prohibited in 1893, but females remained further south until, in 1993, a pregnant female from the Auckland Islands travelled over 400 km north to give birth to a female pup at Taiari Mouth. This pregnant female was nicknamed 'Mum' by the local community. ‘Mum’ remained in the area to raise her pup (named ‘Katya’), and these two females together started the recolonisation of the South Island at Otago. As of 2025, all pups born along the Otago coast were related to 'Mum'.

In 2007, another female born at the Auckland Islands gave birth to a pup in the Catlins. Following the same process observed at Otago, the Catlins population has continued to grow and spread.

There is currently no breeding aggregation at Otago or the Catlins. These females give birth to their pups alone and later bring their pups together at the same sites each year (nicknamed ‘creches’), within three months. This behaviour is similar to that observed at Rakiura.

Diet and foraging

New Zealand sea lions breed on land and forage exclusively at sea. They are carnivores that eat a wide range of prey species.

New Zealand sea lions are active divers that forage on benthic (on the seabed) and pelagic (in the water column) prey. They predominantly eat fish, cephalopods, and crustaceans, although a few individuals are also known to feed on seabirds and fur seals.

New Zealand sea lion diet has been studied using scats, regurgitates, and tissue stable isotope signatures. Foraging behaviours have been studied using satellite tracking tags and depth recorders temporarily glued to the animals’ fur. Diet and foraging behaviours vary between sexes and age groups and between the subantarctic islands, Rakiura and the South Island.

In the subantarctic islands, the diet of adult males and females includes yellow octopus, arrow squid, hoki, hake, rattail, small-scale cod, opalfish and red cod. Females generally dive to 129 m for about 3.9 minutes, with some dives to over 600 m deep for as long as 14.5 minutes.

In contrast, the diet of adult males and females at Otago and the Catlins consists of barracouta, jack mackerel, Maori octopus, arrow squid, red cod, skate, flounder, blue cod, paddle crab, and kahawai. The Otago and Catlins animals generally dive to less than 30 m on shallow rocky reefs and deeper (approximately 60 m depth) on bryozoan thickets.

Great white sharks are the only known natural predators of New Zealand sea lions. In the subantarctic islands, many animals harbour injuries and scars from shark encounters.