Many types of feral animals were introduced to Macquarie Island in the 19th century, including cats, weka (a large, flightless bird from New Zealand), rabbits, rats and mice, with negative impacts on the island's native flora, fauna, geological features and natural landscape values. A Pest Eradication Program has been highly successful in removing these introduced species from the island and restoring the island's unique natural balance. See the Macquarie Island Pest Eradication Project
Macquarie Island is recognised for its rich and diverse animal life. Around 3.5 million seabirds arrive on Macquarie Island each year to breed and moult. Most of these are penguins.
Enormous penguin populations
Four types of penguins breed on Macquarie Island.
Royal penguins are the most numerous with a population estimated at around 850 000. These penguins are endemic to Macquarie Island.They spend seven months of the year at Macquarie foraging offshore for shrimps and fish.
King penguins spend all year on the island. Their chicks take 11 months to fledge so pairs do not breed every year. Over 100 000 breeding pairs occur on Macquarie Island which is the third largest colony of King penguins in the world.They mainly feed on fish and may forage up to 480 km offshore.
Gentoo penguins are also present all year round on the island. This is the only gentoo penguin population in the Pacific sector, mostly these penguins occur in the Atlantic sector. Less than 5 000 breeding pairs at Macquarie Island. They generally feed inshore in shallower waters on squid and fish.
No accurate counts of rockhopper penguins are known, estimates range from 100 000 to 500 000 breeding pairs. Unlike the other three penguin species, rockhoppers do occur in other areas of the Pacific sector, on the southern islands of New Zealand. Rockhoppers spend seven months on Macquarie and feed offshore on shrimps and some fish and squid.
The light-mantled sooty albatrosses are the most abundant of the four albatross species breeding at Macquarie Island. In 1992-3 an estimated 2000 breeding pairs lived on the island. These birds spend a lot of time foraging at sea and are at risk from longline fishing. They breed every second year although on Macquarie they may average once every 3-4 years. Nests are scattered around the coast. Smaller colonies of the black-browed and grey-headed albatrosses occur on Macquarie Island, around 100 pairs each.These are small populations compared with elsewhere.
Less than ten pairs of wandering albatrosses breed annually at Macquarie Island. Although unlikey to have ever been a major breeding site, the present population is believed to be at risk and was more numerous in the past.Chicks take 11 months to fledge. Adults forage over huge distances and may travel thousands of kilometres searching for squid, fish and carrion.
The Macquarie Island cormorant is an endemic sub species of the king cormorant.Less than 800 pairs breed on the main island and the Bishop and Clerk Islets.Great skuas, kelp gulls and Antarctic terns also breed on the island.
Four types of seals breed on Macquarie Island. Three of these are fur seals, the Antarctic, sub-Antarctic and New Zealand fur seals.This is the only island where all three fur seals have established populations. The New Zealand fur seal is the most common on the island, over 2 000 individuals. However most of these are non-breeding males and only an occassional female breeds on the island. The small fur seal breeding population on Macquarie Island consists of mixed colonies of mainly Antarctic and sub-Antarctic fur seals.
The fourth type of seal breeding at Macquarie Island is the elephant seal. Its estimated that around one seventh of the world's population of elephant seal live on Macquarie Island. They breed mainly on the northern part of the island on the most extensive beach areas. They spend their autumn and winter at sea foraging as adults amongst the pack ice of the Antarctic region.
The rocky intertidal and subtidal areas of Macquarie Island support extensive and luxurious growths of seaweeds. The large brown algae, in particular the giant Antarctic kelp is the most obvious providing shade and shelter for other species.
There are more than twice the number of underwater plants species than terrestrial species. A total of 103 benthic macro algae species have been recorded, mostly red and brown algaes.
Large numbers of unique marine creatures
The small marine invertebrates living in the sea around Macquarie Island have been shown to be biogeographically distinct from other areas. There is a high level of endemism in the benthic fauna such as in the molluscs and echinoderms found so far.
Australian Antarctic Division Web Site