Audubon's shearwater underparts are white, as is the head below eye level. The iris is dark, the feet are dull pink with a black wash and black toenails, and the bill is grey, darker towards the tip, and with a pinkish hue. Males and females look alike. Immature birds do not have a distinct plumage, while the nestlings are covered with down feathers, grey above and whitish on the belly. It can be confused with the Manx shearwater ("P. puffinus"), which has white undertail coverts and in direct comparison a longer bill. Other similar-looking species are usually completely allopatric, though the largely
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