If you know the word “prion” at all you probably think of a mis-folded protein that causes neurodegenerative diseases. But it’s also a small family of seven petrel-like species, the largest of which is the Antarctic Prion. The white belly, white eyebrow, black tail tip and distinctive dark “M” shape on the back make it a pretty easy ID.
Slightly smaller than petrels like the Cape Petrel, they are zooplankton and krill specialists. Their bill is adapted to filter-feeding, and they have a gular pouch like a mini-whale to assist in that filter-feeding.
In flight, they are even more aerobatic than the petrels, skimming an inch or so above the ocean surface and then suddenly pivoting back for near-surface krill. It makes them a real challenge to photograph. Unlike Cape Petrels, this species isn’t a ship-follower. We only saw them six times in 24 days.
There are an estimated 50 million Antarctic Prions distributed around the Southern Ocean. The most immediate threats are over-fishing of krill and ocean acidification, which would kill off the krill. But, for the moment, the populations are healthy.
[Some notes on pelagic bird photography. You stand the a ship’s deck, that is bouncing up and down in one to three meter waves. You are holding and aiming a heavy, long-lensed camera, trying to find the bird and then hold the bird in the frame as the boat moves rolls and moves, the bird changes directions and speeds. Most of the birds are black and white, creating very challenging exposure issues. Go ahead and give it a try yourself. WC will wait.]
For more bird photos, please visit Frozen Feather Images.