Antarctica and the Southern Ocean may be inhospitable to humans, but the region is far from lifeless. Hundreds of species are at home in Antarctica, including dozens of varieties of seabirds. The most famous Antarctic seabird is the flightless penguin, but there are many pelagic seabird species as well, including albatrosses, petrels, cormorants, skuas, gulls, terns, and prions.
The sea, sky, and horizon cameras mounted on Saildrone unmanned surface vehicles (USVs) often capture photographs of passing aves. During the 2019 Antarctic Circumnavigation, SD 1020 has caught several different birds on camera.
While our friends at the National Oceanic and Atmospheric Administration (NOAA) were reasonably confident in identifying a juvenile fin whale in an image captured in the Chukchi Sea, it’s somewhat harder to identify birds captured by saildrone cameras, first, because there are so many species, and second, because the general distance from the camera and movement makes it difficult to pick out defining characteristics like size, shape, plumage, and beak.
We suspect the bird in this image, taken about halfway between New Zealand and Drake’s Passage, to be some sort of albatross because of its large wingspan, white belly, and slight dark shading to its wings. But what type of albatross is it?
It’s been suggested that this bird is some type of prion because of the dark plumage on the tail and at the wingtips, as well as the seemingly smaller size.
There are 17 species of penguin that live in the Southern Hemisphere, of which 11 are listed as vulnerable or endangered. There are six penguin species native to Antarctica: Emperor, King, Chinstrap, Adelie, Gentoo, and Macaroni penguins. Though penguins can’t fly, they are strong swimmers and spend much of their life at sea foraging for krill, squid, and fish.
Albatrosses are a family of large pelagic seabirds with a long lifespan—over 50 years. There are some 22 recognized species, most of which live in the Southern Hemisphere. The oldest known albatross, Wisdom, first tagged in 1956 at the approximate age of five, is a Laysan albatross that nests on Midway Atoll in the middle of the North Pacific. Albatrosses prefer to nest on isolated islands in large colonies and usually return to breed in the same colony where they were born.
The Snow petrel is part of the Procellariidae family, which includes petrels, prions, and shearwaters. These beautiful all-white birds are one of only three seabirds that breed exclusively in Antarctica, on the Antarctic peninsula and several nearby islands. Like penguins, they feed primarily on krill, fish, and squid. They tend to fly very low over water but very high over land to avoid predators.
The Antarctic prion belongs to the same family as the Snow petrel but is only about a quarter of the size. Antarctic prions breed at several sites in the Southern Ocean and as far north as New Zealand. One of the largest breeding sites is on South Georgia Island, home to an estimated 22 million pairs.
The Imperial shag is the only type of cormorant found in Antarctica, and the only Antarctic seabird to maintain a nest year-round. They are found only in four nesting sites in the sub-Antarctic zone: on the west side of the Antarctic peninsula, the Scotia Arc, South Georgia Island, and the south-west coast of South America.
There are a number of gulls found in the Southern Ocean, including the kelp gull and southern black-backed gull. The Antarctic tern is a small bird found throughout the Antarctic region. While penguins, albatrosses, petrels, and prions tend to be solitary hunters, gulls and terns hunt and scavenge in flocks for fish and small crustaceans. The Audubon Society calls the South Polar skua a bird-eating bully. While they do forage at sea for krill, they also eat penguin eggs and steal fish straight from the beaks of other seabirds.
It is believed that seabirds in Antarctica and around the world face several threats related to climate changes in the Southern Ocean. The Southern Ocean is known as a “carbon sink” because it absorbs a relatively large amount of carbon from the atmosphere and carries it into the deep ocean. But as carbon levels increase, the ocean becomes more acidic, which may impact the health of the fish and krill that seabirds rely on for nourishment.
Rising sea levels, caused by melting ice in Antarctica and the Arctic and the thermal expansion in the ocean, threaten many low-lying remote islands in the Southern Ocean and further north. Laysan Island is a 15.5 square kilometer (six square mile) atoll northwest of Hawaii and a breeding ground for an estimated six million birds. The elevation of Laysan is at most 1.6 meters (5.5 feet). Sea level is predicted to rise three feet this century, nearly submerging Laysan and other low-lying islands and eroding beaches around the world that birds of all types rely on for foraging and nesting.
The 2019 Antarctic Circumnavigation is an education outreach initiative that uses cutting-edge Saildrone technology to bring data-driven lessons into classrooms around the world. Saildrone has partnered with the 1851 Trust to develop a series of STEM-oriented lesson plans related to important issues facing Antarctica, available free for teachers and students.
The third module, which includes three lessons and a video related to penguins their relationship to the Antarctic ecosystem, is available free for teachers and educators around the world.
Read science-focused blog posts at saildrone.com/missions/antarctica or download the lessons at saildrone.com/missions/antarctica-lesson-plans
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Carl Safina, “How Climate Change is Sinking Seabirds,” Audobon, September-October 2014
Sarah Zielinski, “Some seabirds will be hit hard by sea level rise,” ScienceNews, September 30, 2015
“Sea-Level Rise and Tsunami Vulnerability of Habitat and Wildlife of the Northwestern Hawaiian Islands,” U.S. Geological Survey, accessed May 2, 2019