King penguin population booming on remote Macquarie Island

King penguins are spreading again on Macquarie Island. Photo Kerry Steinberner

King penguins recolonise Macquarie Island
September 2009. King penguins are recolonising the Macquarie Island Isthmus almost 100 years after the populations were destroyed by commercial harvesting.

Between 1810 and 1918 birds from the two large breeding colonies, at Lusitania Bay and the North-End Isthmus, were killed for the blubber oil trade. The North-End Isthmus colony was totally wiped out, while at Lusitania Bay numbers were reduced to fewer than 5000 birds.

Observations by the Australian Antarctic Division have recently discovered that while the Lusitania Bay site was rapidly recolonised, the Isthmus remained abandoned until very recently. MacQuarie Island is one of the remotest places in the world, situated in the Southern Ocean 1,000 miles from the nearest land and equidistant from Tasmania, New Zealand and the Antarctic Continent.

Biologist John van den Hoff said king penguins usually return to their natal (birth) colonies and because the colony at Lusitania Bay was never totally eradicated the birds filled that area first.

170,000 breeding pairs
In 2000, the population at Lusitania Bay was estimated at 170,000 breeding pairs forcing the expanding colony to seek other suitable breeding habitat.

"Up until 1995, no breeding colonies had been observed on the Isthmus at all but now a small colony has established itself at the southern end of the Isthmus at Gadget Gully. Initially the number of birds attempting to breed was low and chick mortality was high, but by August last year, 235 chicks were present," Mr van den Hoff said.

King penguins on Macquarie Island - Photo by Christo Baars