This week at Macquarie Island: 14 September 2018

Completing the colour-wheel of Macquarie Island’s petrels from white-headed to grey we’re now on to blue petrels. Poetically, their scientific name Halobaena caerulea means “the blue sea-walker”. The first report of them is from 1900 when they were described as “exceedingly numerous”. Numbers plummeted through the 1900s until the species was extinct as a breeder on the main island. A handful of tiny populations were found surviving on offshore rock stacks in the 1970s. As a result of their massive decline they are treated as a threatened species under Australian federal and state legislation.

I’m looking at how the population is responding since the eradications, first of cats by 2000, and then rabbits, rats and mice in 2011–2014. The numbers won’t be crunched for some months yet, but already the apparent changes are remarkable. Blue petrels have recolonised the mainland and are expanding outwards from these first returning pioneers. Most dramatic are the scenes at North Head where colonies have spread from the tip to occupy available patches of tussock half way back along Wireless Hill. It will be a race to see if they make it to the Ham Shack before the station itself is moved across the Isthmus. Visiting at night, what have for decades been blank skies are now filled with a swirling mass of birds returning on dusk to the colony. They’re reforming their pair bond and renovating burrows during September before returning to lay eggs in October. At Green Gorge once silent slopes next to the Overland Track become a bubbling wall of noise after dark (visit the Xeno-canto Foundation website to hear the sounds of a colony).

Petrels return to land at night to avoid diurnal predators like skuas and kelp gulls. If you want to find them and get a handle on numbers you really have to join them at night, so September for me is about getting off station and out of the huts at night searching the coastline for the ghostly white flashes as a passing bird is lit up in the dark. Other expeditioners of the 71^st ANARE are helping me visit some of our remote spots, and we’ve got more to come.

Jez Bird

For the average Australian Antarctic (or sub-Antarctic) expeditioner, heading off station for a few days to visit a field hut is one of the many pleasures of our year south. While these are commonly recreational trips, there are also a range of maintenance and repair jobs needed to keep each hut in top-notch condition.

Here on Macquarie Island, we have five full field huts dotted around the coast and one additional shelter (almost as good as a hut, but lacking a few of the luxuries). Most people spending a year here will try to get to each hut at least once, which is no mean feat when the main transport method is foot and the island is almost 13,000 hectares of mud, tussock and hills.

In order to keep everything running safely and smoothly, there are certain things you do when arriving and leaving a hut. No one wants to be the person who forgets to turn off the water valve and freezes the hut supply line, so we all listen attentively to our handy Field Training Officer (FTO) who gives us the run down during our first trip out. After that, individual hut routines are finessed with each passing trip, and by the end of the year we’ll all have it down to a fine art.

So, for this week’s Icy News, we present ‘How to Hut — Macca style’.

Cathryn O'Sullivan