Short-tailed shearwaters (Puffinus tenuirostris), known in Australia as muttonbirds

Short-tailed shearwaters (Puffins tenuirostris) are seabirds of the Procellariidae family. They feed on krill, squid and fish including sardines (called pilchards in Australia) which are used as baitfish and, in frozen form, to pamper young tuna in off-shore tuna farming pens. In Australia, the short-tailed shearwaters are known as mutton birds, also written in one word as compositum muttonbird. Biologically, they are more interesting than linguistically [1]:

The short-tailed shearwaters (Puffins tenuirostris) make one of the longest migrations of any bird, flying annually from their nesting sites in the Aleutian Islands and Japan to South Australia, a round trip of twenty thousand miles. Known as muttonbirds here because the early settlers plucked them from their burrows and ate them when other food was scarce, they are, like many other seabirds, competent in the air, on land, and in the water. [...] Muttonbirds are not plunge-divers like the gulls and terns, but usually wait on the surface, like ducks, poking their heads underwater to spot a sinking baitfish. They will then dive to catch the fish; properly positioned, you can see them “flying” underwater in their pursuit. They usually resurface—looking perfectly dry because their feathers are waterproof—and sit on the surface like ducks, but occasionally they will do something that startingly emphasizes their mastery of multiple elements: from underwater swimming they break the surface and keep right on going, passing through the water/air interface and taking flight.

Puffins tenuirostris Dictionary
Scientific name: Puffins tenuirostris (Temminck, 1836)
English common name: Short-tailed shearwater
French common name: Puffin à bec grête
German common name: Kurzschwanz-Sturmtaucher (also: Millionen-Sturmtaucher [4])
Spanish common name: Pardela cola corta

References
[1] Richard Ellis: Tuna • Love, Death and Mercury. First Vintage Books Edition, July 2009; page 7.
[2] Puffinus tenuirostris, Short-tailed Shearwater at http://www.borealforest.org/world/birds/short_tailed_shearwater.htm
[3] Taxonomy and Nomenclature: ITIS Report
[4] Grzimeks Tierleben • Siebenter Band • Vögel 1, page 150.