Saturday, January 9, 2016

Hobart GP Sally Hildred takes the pulse of penguin colony in Antarctica

Sally Hildred conducts penguin counts near John O’Groats last month. Pictures: DAVID KILLICK
A COUNTING task may not seem like much of a challenge for a highly qualified doctor like Sally Hildred but conducting a thorough census of adelie penguins at Antarctica’s Cape Denison is no easy feat.
The Hobart GP, who is the medical officer for the Mawson’s Huts Foundation field party visiting the area this summer, has conducted a survey of penguin nests at the site for Australian Antarctic Division scientists.
The count took eight days, during which she braved subzero temperatures, strong winds and the close attention of penguin-eating skuas.
And that’s without mentioning the distinctive smell of the crowded penguin rookeries as she circled with her GPS receiver, a notepad and a handheld clicker.
The knee-high adelie is the archetypal Antarctic penguin and makes its summer home in nests of pebbles on rocky outcrops in the few ice-free areas along the Antarctic coast.
The presence of a huge iceberg known as B9B offshore from Cape Denison is believed to have cut their numbers in the area as they now have to walk up to 20km across the sea ice, which has built up in its lee, to feed.
Dr Hildred said that when she started her count, many of the penguins were sitting on eggs. The young have now hatched and are growing quickly.
“I was surveying around the colonies with a GPS, tracking around each of the colonies at a distance of four to five metres so you don’t disturb the penguins,” she said.
An adelie penguin checks on her chicks at Cape Denison.
Dr Hildred would “draw” a GPS track around larger groups of birds and mark smaller groups with a waypoint and conduct a manual count.
“It’s all scrambling up and down the rocks, occasionally you get a nice flat bit but that is the exception, not the rule. Quite a few of them are out along the ridges,” she said.
“It was a lot of climbing and scrambling and in some areas there were a lot of steep drop-offs. It was a matter of figuring out how you were going to draw a circle.
“I found I couldn’t do it when it was too windy because it was too hard balancing on the rocks. It’s too dangerous and you can’t write in your notepad.”
She said the feeling of being an interloper in the middle of a large group of penguins was sometimes a little unnerving, given their large numbers and the other local wildlife was alert to her presence as well.
“When I was waking along, sometimes I’d hear a sudden cry of alarm because there was a skua nearby on a nest and you’d have the male come over and have a look and sometimes from out of a crack in the rocks you would hear a snow petrel sounding the alarm.”
The data Dr Hildred has collected will be analysed before Australian Antarctic Division scientists are able to put a more exact number on the thousands of penguins in 142 separate colonies, ranging from just a handful to hundreds of residents.
The last comprehensive count of adelie penguins at Cape Denison was carried out in 1999.


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