Black-vented shearwater Black-vented shearwater The black-vented shearwater ("Puffinus opisthomelas") is a species of seabird. The bird is 30–38 cm in size, with a 76–89 cm wingspan. Formerly considered a subspecies of the Manx shearwater, its actual relationships are unresolved. This species is pelagic, occurring in the Pacific Ocean and the Gulf of California. It comes closer to land than most other shearwaters, so it sometimes can be seen from shore. It predominantly nests on offshore islands off north and western Baja California, namely Isla de Guadalupe, Islas San Benito and Isla Natividad. It is fairly common off the United States coast of
Gwennap Head 15 October each year and most of the recording was by volunteers who spent up to twelve hours a day on seawatch. The main targeted species were Balearic shearwater ("Puffinus mauretanicus") and basking shark, along with the ocean sunfish (or common mola). Marine mammals such as whales, dolphins and grey seal ("Halichoerus grypus") were additional main targets. During a seawatch on 28 August 2015 a red-billed tropicbird ("Phaethon aethereus") was seen over the Runnel Stone, a bird that usually frequents tropical areas. Gwennap Head is part of the Land’s End granite massif with shallow, free-draining and acidic soils. The dominant