Wednesday, 20 June, 2018

Previously unknown colony of 1.5 million penguins found on Antarctic islands

Even in the austral summer the surrounding ocean is filled with thick sea ice making it extremely difficult to access. The Danger Islands are located in the northern peninsula of Antarctica and are home to 751,527 pairs of Adélie penguins Previously unknown colony of 1.5 million penguins found on Antarctic islands
Nellie Chapman | 03 March, 2018, 02:52

According to experts, more than 1.5 million Adelie penguins have now been found on the Danger Islands. Their results, published this month in the journal Scientific Reports, show that there are now more than 750,000 breeding pairs of Adélie penguins in the Danger Islands-more than the rest of Antarctica combined.

"Basically these islands were covered in penguins", Michael Polito, an assistant professor of oceanography and coastal sciences at Louisiana State University and coauthor of the paper, told BuzzFeed News.

"Is certainly surprising and it has real consequences for how we manage this region", explained Heather Lynch, the study's author and a researcher at the Stony Brook University. The scientists used new drone technology to get a better count of the penguins.

"The area is covered by heavy sea ice most of the year, and even in the height of summer it is hard to get into this region to do surveys".

Then followed a field expedition for a census using a combination of drone footage, pictures taken on the ground, and an old fashioned walk-about headcount. "You can then stitch them together into a huge collage that shows the entire landmass in 2D and 3D", said Hanumant Singh, professor of mechanical and industrial engineering at Northeastern University.

The result is of major significance because it would appear the archipelago has somehow avoided the recent Adélie declines documented elsewhere on the peninsula, particularly on its western side.

Adélie penguins (Pygoscelis adeliae) have always been thought to be disappearing from our planet due to human encroachment on their territory, and especially from global warming affecting their food source, mainly krill, which are disappearing more rapidly as sea ice in the region ebbs.

It turns out, population surveys were ignoring a super-colony just off the coast of the Antarctic Peninsula's northern tip.

Scientists suspect that decline has something to do with reductions in sea-ice, which is an important habitat for krill, the small crustaceans that form a key part of the penguin diet.

A tiny group of islands in the Antarctic ocean, called the Danger Islands, are home to almost 1.5 million penguins.

"In the past we've looked at this on the West Antarctic Peninsula versus places like Elephant Island (further to the north)".

And Dr Lynch added: "The other point worth making is that these islands are right in the mix for a couple of marine protected areas that are being proposed. We want to understand why", said Stephanie Jenouvrier, a seabird ecologist at WHOI and coauthor of the study, in the release.

Dr Peter Fretwell from the British Antarctic Survey knows the team but was not involved in this study.

"It's a gyre, a spinning caultron of ice, and because its so icy, the eastern side of the peninsula is very icy", he said. It's also the middle of the breeding season for penguins, which helped in counting them.