muttonbird, any of several shearwaters (oceanic bird species), whose chicks are harvested commercially for meat and oil. The species principally utilized are the short-tailed, or slender-billed, shearwater (Puffinus tenuirostris), in Australia and Tasmania, and the sooty shearwater (P. griseus), in New Zealand. Certain of the large petrels (Pterodroma species) are also harvested occasionally, as are some fulmars.