For the most part, the birds which visit the Arctic and Antarctic are migratory, able to escape the coldest months by flying to warmer climates. Some, however, hang around all year round, and the most prominent of these is surely the snow petrel. These resilient little birds spend their entire lives moving around the vicinity of the Antarctic, subsisting on the krill and fish which mass in the icy water.
They are typically found nesting in their hundreds on cliff faces, or rocky sections of coastline. This is because they look for hollows and crevices to use as nests, such that their chicks will be kept out of the wind. It’s also a measure against nest raiding predator birds, but if that doesn’t work, their second line of defense is aggressive vomiting. Yep, not kidding, they will literally spew a blast of foul, acidic, partially digested fish at their aggressors, and many an unfortunate researcher or nature photographer has found this out the hard way.
During the winter, such nesting sites are all iced over, so you would think that they would fly further out to find more suitable hunting grounds, but in fact the opposite is true. They move further south, into colder, more adverse conditions, they’ve even been seen in the vicinity of the south pole. They do this because of the abundance of food beneath the sea ice, and the flat out lack of competition for it.
Like other Arctic birds, their feathers are waterproof, covering a layer of down which traps warmth and keeps it close. The muscles with control their feet are drawn back to the top of the leg so that the cold can’t get in that way, and their relatively small size minimizes energy expenditure.
Perhaps most amazingly, though, they can drink salt water. Their tubular nostrils can expel the more saline parts of seawater from salt glands near their eye sockets, such that by the time the water reaches their digestive system, it can be processed without doing them any harm. During the winter, they largely feed by fishing into tide cracks, sitting on the edge of the ice and waiting for groups of krill to rise to the surface. Sometimes they will even deliberately shadow a seal, since it will scare krill to the surface as it moves around below.
Callum is a film school graduate who is now making a name for himself as a journalist and content writer. His vices include flat whites and 90s hip-hop.