יסעור כהה Ardenna grisea

Medium-sized, dark brown shearwater with silvery flashes on underwings. Narrow wings with quick, deep wingbeats. Widespread and common, especially in the Pacific; can sometimes be seen close to shore. Can be in massive flocks. Extremely similar to Short-tailed Shearwater, but Sooty is heavier and has straighter wings; also look for slightly longer bill and less rounded head. Brown plumage is reminiscent of Flesh-footed Shearwater, but Sooty is narrower-winged and has a smaller, all-dark bill.