New Zealand Sea Lion

New Zealand Post is proud to continue to support Te Puna Whaiora – The New Zealand Foundation for Child and Family Health and Development with its annual Children’s Health stamp issue.The 2012 Children’s Health stamp issue features the New Zealand sea lion. This playful mammal is one of the rarest species of sea lion in the world.

The issue comprises of three postage stamp, one specific shaped miniature sheet, and two First Day Covers. All  issue of stamps features pup and sub-adult of New Zealand Sea Lions.

The New Zealand sea lion (Phocarctos hookeri) also known as Hooker's sea lion or whakahao in Māori is a species of sea lion that breeds around the coast of New Zealand's South Island and Stewart Island/Rakiura to some extent, and to a greater extent around the New Zealand Sub-Antarctic Islands, especially the Auckland Islands.

The principal breeding colony accounting for 86% of annual births is at the Auckland Islands, with a smaller number breeding at Campbell Island (Chilvers et al. 2007).New Zealand Sea Lions do not appear to be migratory, although they disperse widely over their range during the non-breeding season (Robertson et al. 2005)

New Zealand Sea Lions are large heavy-bodied sexually dimorphic animals. Adult males are 1.2-1.5 times longer and 3-4 times heavier than adult females.Adult males are 240-350 cm long and weigh 320-450 kg and adult females are 180-200 cm long and weigh 90-165 kg.

Adult females' coats vary from buff to creamy gray 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.

New Zealand Sea Lions take a wide variety of vertebrate and invertebrate prey. Frequently-taken species include: opal fish, octopus,  oblique-banded rattail fish, scalps, squid and crustaceans. Prey is taken in both benthic and pelagic habitats.

Newborns are approximately 70-100 cm long and weigh 8-10 kg (Chilvers et al. 2006). Pups are born in a thick long dark brown lanugo with a lighter crown, nape, and mystical area, and with a pale stripe on the top of the muzzle, originating on the crown.

Breeding and hauling out occurs on sandy beaches . For the fist six months of life, the pups explore the freshwater creeks and pools around the beach . The adults often wander as far as two kilometres inland and can be found resting in forests or on grassy cliffs.

Males become sexually mature at the age of 5 years. The age of maturity for females is 3-4 years. Gestation lasts 12 months. Pup mortality at the end of one year is about 35%. Males live at least 23 years and females to at least 26 years.

The breeding season for the New Zealand Sea Lion begins in late November when adult males return and establish themselves on territories through displays, vocalizing, and fighting . Breeding and hauling out occurs on sandy beaches . For the fist six months of life, the pups explore the freshwater creeks and pools around the beach . The adults often wander as far as two kilometres inland and can be found resting in forests or on grassy cliffs

 
 

Adult males are a significant source of mortality to pups, occasionally killing them outright and also through incidents of cannibalism. Pups are also trampled and killed by adult males challenging other males during territorial disputes.

New Zealand Sea Lions were once more abundant, with a much more extensive range that included the North and South islands of New Zealand. The Maori people of New Zealand have traditionally hunted sea lions.Commercial sealing in the early 19th century decimated the population in the Auckland Islands, but despite this, continued until the mid-20th century, when it was halted.