Meet the Southern Giant Petrel #seabirdsaturday

By: Erin Pickett

I have overheard about three different people today call the weather “gross”, which is understanding given the winds around here are gusting over 40 knots and it’s been raining all day, but I’m kind of enjoying it.

Due to safety concerns, we don’t take our Zodiac boats out if the winds are higher than 20 knots, so Logan and I have been occupying ourselves with indoor tasks today. I thought I’d take the time to share a few photos with you. Yesterday while Logan and I were surveying for whales we came across a group of giant petrels sitting on the water along with a few hovering Wilson’s storm petrels. Upon closer inspection we found the petrels scavenging on a fresh penguin carcass. Leopard seal leftovers perhaps?

Southern giant petrels are very cool! They range throughout the entire southern ocean and breed on many sub Antarctic islands and along the Antarctic Peninsula. They are large birds, with a wingspan of 150-210 centimeters (over 6 feet!). The scientific name of the giant petrel is Macronectes giganteus, which comes from Latin and Greek root words meaning “large”, “swimmer”, and “gigantic”. Another fun fact- the name Petrel refers to the story of St. Peter walking on water. Petrels have webbed feet that allow them to run on the surface of the water when they take off (they also make unique tracks through the snow).

The seabird team here at Palmer is monitoring the local population of giant petrels that are currently raising their chicks on nearby Humble Island. While they are raising chicks, mating pairs take turns guarding their nest and making foraging trips to obtain food for themselves and their young. Giant petrels are scavengers and will feed on carrion (e.g. dead and decaying elephant seals) and they are also predators that will kill live birds by taking them off the surface of the water.

Check out the photos to see what I’m talking about!

 

The finale: the Rosenthal Islands

Erin Pickett-

The Palmer LTER 2016 research cruise has come to an end and I am back at Palmer Station. In addition to a fantastic espresso machine, Palmer Station also comes with the added benefit of more internet bandwidth and a phone to call home. I thought while the memories are still fresh and my friends and family are beginning to ask, I’d better write down a few of my favorite field adventure moments.

Thinking back, there are a few common themes that all of these favorite moments have in common, and they are; high winds and snow stinging my face, dramatic cliff faces and rocky islands, shoes covered in penguin guano, sightings of whale spouts, and seabirds I have never seen before.

Overall, there were far fewer whales seen on this cruise than there have been in the past. Luckily, I was able to keep busy anyway, because when we weren’t finding whales I was assisting the seabird team in their pursuit of penguins. Toward the end of the cruise most of the science projects happening on the ship were wrapping up and the birders and whalers were given more freedom to direct the show. This meant we were able to work with the captain of the ship to chart courses to areas where we thought we might find whales and to rarely visited islands with colonies of Adelie, gentoo, and chinstrap penguins.

The first group of islands we visited were just east of Prospect point, called the fish islands. We used a handheld GPS and hand-drawn maps to navigate around a group of small rocky islands collectively named the minnows. Carrie and Darren (the “birders”) and I hopped on and off our skiff to count the chicks and adult penguins on each island. Meanwhile, our boat driver was keeping an eye on the wind and the icebergs surrounding us so that we wouldn’t find ourselves trapped in the bay if the sea ice became packed in by strengthening winds. Our ride back to the ship that day was quite wet due to a lot of wind chop, and we spent the rest of the afternoon drying our gear out and warming up so that we would be ready to return back to the minnows that evening to collect Adelie penguin diet samples.

Giovanni Fattori (https://commons.wikimedia.org/w/index.php?curid=11939457)
Prospect point is colored in red in the center of the peninsula, with Anvers Island and the Gerlache straight to the North. Image credit: Giovanni Fattori (https://commons.wikimedia.org/w/index.php?curid=11939457)

Diet sampling is a critical part of the birders work during the LTER cruise. Collecting diet samples from Adelie penguins over a long time period and over large geographical distances allows us to monitor how changes in sea ice along the peninsula are impacting top predators and their prey. We had a successful trip back to the minnows that evening and collected fresh diet samples from five Adelie penguins that had just returned home from foraging trips.

Two days later we arrived at the Rosenthal islands, which are located on the west side Anvers Island. Our goal at the Rosenthal’s was to census the local penguin colonies. The Rosenthal’s were unlike anywhere else I have been yet, with jagged islands set dramatically near the base of a large glacier and waves crashing over nearby shoals and icebergs. Southern giant petrels and skuas glided over our heads while groups of penguins porpoised around us. At the first island we came to we got to see a king penguin, a rare sighting in this area.

Luckily there were six of us to count the thousands of Adelie, gentoo and chinstrap penguins that were scattered in colonies all over the islands, but it still took most of the day to complete our counts. After one last trip through the Gerlache straight at sunset, we arrived back at Palmer Station.

I hate to admit that I didn’t have my camera with me at Prospect point and at the Rosenthal’s, so until I get a few from the rest of the field team here are a few from the last week of the cruise…

Torgersen Island Adelie Penguins

Logan: Today I had the pleasure of visiting the Torgersen Island Adelie Penguin colony. We can see the colony from station at a distance. We circled the island in the zodiac and I admired the tall peaks of jagged rock that these penguins somehow managed to traverse to get to the nesting sites. Unfortunately we had to approach the loading zone down wind of the colony, an area you do not want to be if you have a weak stomach. Immediately my stomach began to churn as I smelled the distasteful odor of Adelie guano that lined the rocky terrain in a pink shear.

We landed on the island and I quickly began to traverse the rock terrain to the peak of the island near the colony nesting sites. We were instructed earlier in the day that the chicks had already hatched and that we were to remain at distance as to not distract the parents with chicks. The Brown Skua, a large predatory bird, takes advantage of unprotected chicks, carrying them away from the colony to feed on the tiny brown fluff balls. I managed to find a good spot to sit on the rocks and turn on my GoPro and just sit and observe the activities of these beautiful birds. The noise that this colony could produce was outstanding. I watched these birds interact with each other in many different ways. Some would raise their necks high into the air as a sign of what I believed to be courtship, while others were just laid on the ground trying to stay cool. This particular colony is in decline. These penguins are an ice dependent species, and as the climate in this area continues to warm, this colony will likely disappear.

Erin, Ari, and Doug are still out on the LMG trying to place our suction cup tags on nearby humpback whales. Have not heard from them yet, but hopefully I get a call that a tag has been placed. That is all for today!!!