New Zealand is the Penguin Capital of the World, with more than half of all species breeding in our territory. What can they tell us about our seas?
Closest to the mainland lie the Snares, with their own endemic species of crested penguin. These flipper-powered torpedoes swim at speeds in excess of 20 km/h as they chase their prey of squid, fish and krill.Royal penguins make their way along a trail from the colony at Sandy Bay, on the east coast of Macquarie Island.With their bright yellow plumage, jet black heads and distinctive shape, king penguins are similar in appearance to the closely related emperor penguin of Happy Feet fame. But unlike their Antarctic cousin, king penguins live on isolated islands in the Southern Ocean, are smaller in stature and breed during the summer months rather than brave the polar winter. On Macquarie Island, king penguins were nearly wiped out in the early 20th century by a commercial operation headed by the notorious entrepreneur—and former Invercargill mayor and member of Parliament—Joseph Hatch, whose team of ‘oilers’ clubbed to death three million penguins over the course of three decades and rendered them into oil. The enterprise drew criticism from British zoologist and politician Sir Walter Rothschild and later from polar explorer and scientist Sir Douglas Mawson, resulting in one of the earliest public conservation concerns for the greater Antarctic region. As a result, the oiling industry was halted before the total destruction of the colony, and today the penguin population on Macquarie Island numbers in the hundreds of thousands, many nesting in the shelter of rusting ‘digesters’ which boiled their forebears. The colonies are noisy and acrid, with chicks trumpeting for their parents and adults fiercely protecting their patch. Though ungainly on land, king penguins are swift at sea, travelling hundreds of kilometres on a single foraging trip and diving to depths of 200 metres.The little blue penguin’s unique sheen is created by nanostructures in the feathers that scatter light in such a way as to create an aquatic hue. Interlocking feathers are a penguin’s waterproof insulation from the cold that would otherwise kill them, so they take meticulous care of them—carefully preening and oiling their plumage after each swim. They must remain ashore for several weeks during their annual feather moult, during which time they are unable to feed and lose a lot of condition.Snares crested penguins take to the sea to forage for food. Highly productive conditions around the Snares Islands make them an ideal place to raise their young. Stable isotope studies of living and historical specimens show that ocean productivity and the diet of the penguins here have remained unchanged for 120 years. This is in stark contrast to Campbell Island, where a change in ocean productivity appears to be responsible for a massive decline in rockhopper penguins. The Snares’ environmental stability and pest-free status make them invaluable as a scientific control for penguin studies around the world.
