The chinstrap penguin
© Kim KlistaThe chinstrap penguin
What makes a tiny penguin set out on an epic journey through a vast ocean with seemingly little hope of returning home in one piece?

Antarctic researchers are not actually sure, but when one little chinstrap penguin made a very rare appearance on remote Macquarie Island recently there was great excitement.

The chinstraps are cousins of the more common adelie penguins, but the nearest colony of chinstraps is about 1,500 kilometres south of Macquarie Island

There have only been five chinstrap sightings on "Macca" since 2013, and 44 since 1953.

Australian Antarctic Division penguin biologist Barbara Wienecke said most chinstrap populations live on the Antarctic Peninsula, South Orkney Islands and South Georgia.

"Macquarie Island is certainly a paradise for penguins, but the species that usually breed there do not include the chinstraps," she said.

"It is always exciting when people see birds that are a long, long way from what is considered their normal range by biologists, but clearly, what do we know?"

"A bird is called a 'vagrant' once they are several hundred kilometres out of the range from what they are usually expected, and the nearest colony of chinstraps would be about 1,500 kilometres south of Macquarie Island, so it is one heck of a distance to swim."

Dr Wienecke said when penguins were swimming around the ocean they did not usually travel on a north-south trajectory and it was not clear why this one turned up so far from home.

"It is always difficult to figure out birds' motivations," she said.

"The problem is, particularly for the young birds, we don't really know how far they actually disperse.

Penguin may simply be exploring

Then it was off to the beach to meet some local kings and a gentoo penguins.
© George Brettingham-Moore AAD Then it was off to the beach to meet some local kings and a gentoo penguins.
Dr Wienecke said is was not likely the penguin simply got lost.

"Birds are extremely good navigators unless they have some some sort of genetic abnormality that would prevent them from navigating properly, which is possible but probably extremely rare," she said.

"So young birds who have got no need to be anywhere near their breeding colonies, they usually have several years when they can explore the southern ocean and sometimes they literally just take a turn and go elsewhere, where possibly not too many have gone before."

Dr Wienecke said it was unfortunate that such random visits afford little opportunity for scientists to learn more about the species' travel habits.

"It would be fantastic if we had a program in place and equipment on the island to put a little satellite tag on the bird and actually see where it would go when it leaves Macquarie Island, but it is impossible to plan for such events, because you don't know when they are going to happen," she said.

She said it was not as simple as popping a spare tracking device on the bird and seeing where it wanders.

"I mean, we can't just go out and harass birds just because we think it's a wonderful idea — we do need to have properly assessed and evaluated research programs in place, we do need ethics committees approvals — there is a whole raft of documents that need to be in place before we can actually do something like that," she said.