These very abundant seabirds are uncommon off Oregon in winter. Their arrival coincides with some of the Pacific Northwest's stormiest weather. Complicating detection difficulties is their identification; they look very much like the abundant sooty shearwaters - all dark, but slightly smaller with shorter bills and tails.
Studied on their Tasmanian breeding grounds continuously for over 45 years, once they leave for the open ocean little is known about them. Popularly know as "muttonbirds," they have been harvested as food for centuries on their southern seas breeding islands. Even today, up to 300,000 chicks are harvested in Tasmania each year.
In Oregon, it is an uncommon to fairly common late fall and winter transient; irregular spring transient offshore. It's occasionally seen from shore in early winter, sometimes in large flocks.