Adult females' coats vary from buff to creamy grey with darker pigmentation around the muzzle and the flippers.

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] 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.

[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 after Mum gave birth.

[12][14] 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.

[15] Recent DNA information indicates the New Zealand sea lion is a lineage previously restricted to subantarctic regions.

[17] 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.

[21][22] New Zealand sea lions are in turn preyed on by great white sharks, with 27% showing evidence of scarring from near-miss shark attacks in an opportunistic study of adult New Zealand sea lions at Sandy Bay, Enderby Island.

[30][31] However, the New Zealand Ministry for Primary Industries considers research on which this prediction is based is low quality and 'should not be used in management decisions'.

[32] In late February 2013, the first observed sea lion mortalities in the Auckland Island squid fleet in three years occurred.

[36] In August 2013, the seasonal southern blue whiting fleet captured 21 male sea lions in fishing grounds more than 100 km off the Campbell Islands.

The government responded to the captures by requesting the vessels try sea lion exclusion devices (SLEDs) to reduce this bycatch.

[43] The Auckland Islands population has displayed numerous indicators of food limitation during the recent decline in breeder numbers, including: poor maternal condition, delayed maturation, years with very low pupping rate, low survival of pups born and long-term shifts in diet composition.

[49] On 12 March 2014, the Conservation Minister Nick Smith was quoted as saying an "excessive focus on fishing bycatch" existed and 300 pups had died the previous summer from an as yet unidentified disease.

[50] The mainland population was estimated to reach 1000 animals by 2044, leading to issues of 'marine protected areas, local fishing quotas and numbers management'.

[3][9] In order ensure the protection of New Zealand sea lions, the Department of Conservation works to engage with local communities and spread awareness on this species' recolonisation and behaviour.