Antarctica is a great place to do a little bird-watching. More specifically, it’s a great place to see seabirds, which are sustained by the sea and comprise nearly 3 percent of all 10,000 bird species.
What’s so special about seabirds? They typically live longer, are bigger, postpone breeding until they’re older, and have fewer kids than land birds. They also wander more than other birds and are known for racking up serious air miles during cross-continental migrations and regular fishing trips.
Seabirds need the ocean for sustenance. They hunt on the water’s surface as well as under the water, and some even feed on each other. Most seabirds have webbed feet for surface swimming and diving. Though these birds primarily make a living at sea, they still rely on the land for mating and child-rearing. Seabirds typically nest in colonies ranging in size from a few dozen to millions of individuals. Most seabirds breed once a year, and some (albatrosses) even breed every other year.
Depending on their specific ecological niche, seabirds vary from each other in lifestyle, diet and behavior. Some species are pelagic. They breed in Antarctic cliffs above the ocean and on the surrounding sub-Antarctic islands, but winter at sea. Non-pelagic seabirds are mostly coastal, while some species live along the ocean for part of the year and then nest inland near wetlands and lakes.
Pelagic species – like albatrosses and petrels – have longer wings that are designed for low wing loading. The Wandering Albatross boasts the largest wingspan of any living bird (up to 4 m / 12 ft) with wings that are adapted perfectly for gliding, also called dynamic soaring. They’re not built for power moves and acrobatics. Diving birds typically have shorter wings and are more maneuverable.
Seabirds are divided into three categories:
Tube-nosed birds (procellariiformes) are expert fliers and include albatrosses and fulmars, such as petrels, prions, shearwaters, and southern fulmars. These guys spend a lot of time roaming the ocean for food. Wilson’s storm petrels are comparatively small, but they breed only in Antarctica and migrate farther than any other bird species.
Charadriiformes are actually water birds, like gulls, terns, sheathbills, and skuas. Sheathbills are the garbage collectors of the Antarctic, and they employ their talents around penguin colonies. Skuas were called pirates by early explorers because they steal eggs and chicks of penguins and other birds.
Pelecaniformes, including pelicans, typically stay in the northern hemisphere. The exception is cormorants such as shags, which prefer Antarctic waters and sub-Antarctic islands. Shags usually nest on ledges and cliffs, and they hunt in relatively shallow water for small fish and invertebrates. Shags don’t have waterproof feathers, so they indulge in avid feather-drying on land.
A few small groups of waterfowl also call the sub-Antarctic islands home. They stay in sheltered areas or coastal regions and feed in shallow waters. Gray ducks, yellow-billed and kerguelen pintails, and specked teals live there, but summer brings other visiting species.
Some Antarctic seabirds have close relatives in the north, including the following north-south species pairs: Arctic/Antarctic terns, Great/Antarctic skuas, and northern/southern fulmars.
[TRIP TRIVIA: Birds love ships. When cruising around Antarctica, enjoy the albatrosses and petrels that follow and soar alongside you at eye level. Wind around a moving ship creates updrafts and currents that seabirds use to their advantage.]
Pass The Salt
Seabirds often spend months at sea with no access to fresh water. With less-efficient kidneys than humans, how do they handle the excess salt in sea water?
Seabirds have two small salt glands that are 10 times more efficient at removing salt than the birds’ kidneys. These glands are positioned in a small groove above their eyes. Blood carries the salt through the salt glands, where it’s excreted in a saline-loaded solution that drains into the bird’s nasal cavities. This salt solution typically drips from the bird’s nostrils to the end of its bill.
Instead of using a salt-shaker, seabirds “do” the salt-shaker… they flip their noses and shake off the excess drops of salt.