Day 4: The South Shetland Islands


Half Moon Island, Antarctica

December 21, 2016

Another 5 AM morning today, but I was rewarded with a variety of new birds.  We were still in the Drake Passage, but now south of the Antarctic Convergence.  Light-mantled Albatross, Southern Fulmar, Cape Petrel, and Black-bellied Storm Petrel were all visible from the bridge.  I did not see any of these birds yesterday, when north of the Convergence.

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We also saw our first whales of the trip, skillfully identified by Dr. Conor Ryan from the bridge of the ship.  I was very impressed with his ability to identify whales to the species level by the shape and size of the blow they emanate.  We got great looks at both Fin Whale and Humpback Whale.  Captain Oliver Kruess adeptly maneuvered the ship to follow the whales, and they ended up seeming to race they ship.


Fin Whales (Balaenoptera physalus)

I also attended a very informative talk by naturalist Doug Gualtieri on the penguins of the Antarctic.  I learned that the three species of penguins we are most likely going to see on this trip – the Adelie, Chinstrap, and Gentoo Penguins – are the sole members of a group of penguins called “brush-tails” (genus Pycoscelis), named so because of their proportionally large brush-like tails.  I also learned of a white variety of adaptations that allow penguins to better survive to reproductive age in the harsh Antarctic.  One important adaptation is countershading, namely the distinctive black back and white belly penguin phenotype.  Penguins feed in the ocean and approach their prey from above, and the white on the belly makes it harder for their prey (fish, krill, etc.) to see them, as they blend in with the surface of the ocean (as viewed from below).  Their black back makes it harder for their predators (Leopard Seals, etc.) to see them from above, as they blend in with the ocean depths.  I also learned that penguins (like the pelagic birds of the order Procellariiformes) contain a desalinization gland for excreting excess salt from the blood.  Many other unique adaptations allow penguins to better survive the Antarctic cold:

  1. Unique size – Penguins are larger birds, and this large size means a smaller surface area to volume ration, and accordingly, less relative area per volume to dissipate heat.
  2. Unique fat layer – Penguins contain a layer of fat (blubber) under the skin which serves to keep them warmer.
  3. Unique feathers – Penguin feathers are incredibly densely packed, which aids in waterproofing.  These feathers also contain both downy and rigid parts, serving to create downy and rigid feather layers.  The downy layer serves to trap an insulating layer of air.
  4. Unique oil gland – Penguins secrete oil from a gland located near their tail to make their feathers more waterproof.  They spread this oil throughout their feathers during preening.
  5. Unique bones – Most birds have hollow bones to aid them in flight.  Penguins, however, have solid, thick, dense bones, an adaptation for their life in the water.  Their bone structure has also adapted to accommodate their lifestyle of swimming (as opposed to flying).
  6. Unique feet – Penguin feet contain strong toenails, which help in gripping ice and climbing rocks.  Penguins also utilize a unique system of blood flow to modulate their temperature, especially in exposed areas like the feet.

Around midday, we had our first siting of land: the South Shetland Islands.  Our transit toward these islands for our afternoon landing was punctuated by ice bergs, porpoising Gentoo and Chinstrap Penguins, and Brown Skuas and Antarctic Terns buzzing the bow.  The landscape was as first viewed was extremely barren, appearing to be solely ice, snow, and brown rock.  It was amazing to me to think that so much life thrives here.

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Our first landing was at Half Moon Island, located in the South Shetlands between the much larger Livingston and Greenwich Islands.  Before leaving the ship, I had to go through an extensively decontamination.  All of my gear was carefully vacuumed and scrubbed to eliminate the possibility of introducing any invasive organisms to this fragile ecosystem.


Decontamination in the mud room

After decontamination, we hopped in a Zodiac (a small, inflatable, motorized boat) for transit to the island from the Explorer.  Upon exiting the Zodiac, I immediately spotted my first penguin on land – a small Gentoo, bathing in the water.  The penguin was standing only around 5 meters from me!  During a short hike up Xenia Hill, a topographic high on the island, we encountered a small breeding colony of South Polar Skuas.  Descending the other side of the hill, we encountered Weddell Seals basking on the snow and ice.  It is simply amazing to witness how Antarctic wildlife behaves around humans.  It is almost as if curiosity takes precedence over fear.

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The hike ended with a visit to a nesting colony of Chinstrap Penguins.  Males had constructed very symmetrical nests for their mates using small gray stones.  Eggs were clearly visible in the nests (2 per nest), and the male and female in each breeding pair would take turns siting on the nest to keep the eggs warm.  Snowy Sheathbills were also nesting in the area.  The only land-based bird of the Antarctic, the pure white plumage of this sheathbill is somewhat misleading, as they are known to feed on dead animals and feces.

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Back on the ship, after another important decontamination of our boots, we continued further south to Deception Island.  The island is a still-active volcano, and it is shaped like a ring with an extremely narrow entry point (only 750 ft. wide!) called Neptune’s Bellows.  It was riveting watching Captain Kruess navigate the large Explorer through this tiny gap.

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Overnight, we will be crossing the Bransfield Strait toward the western side of the Antarctic Peninsula.

David Walker
Grosvenor Teacher Fellow

Antarctica Expedition
National Geographic Society
Lindblad Expeditions


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