St Levan common species such as northern gannet ("Morus bassanus"), Manx shearwater ("Puffinus puffinus"), common guillemot, ("Uria aalge") and razorbill ("Alca torda"), as well as rarer birds such as Balearic shearwater ("Puffinus mauretanicus") and Cory's shearwater ("Calonectris borealis"). The headland of Tol-pedn (or Gwennap Head) is favoured by birdwatchers and many travel the length and breadth of Britain to track rare seabirds. Some of the butterflies that can be found on the coast include grayling ("Hipparchia semele"), silver-studded blue ("Plebejus argus"), small pearl-bordered fritillary ("Boloria selene") and wall ("Lasiommata megera"). There is also a day-flying moth, the thrift clearwing ("Synansphecia muscaeformis"); the
Tropical shearwater Tropical shearwater The tropical shearwater ("Puffinus bailloni") is a seabird in the family Procellariidae formerly considered conspecific with Audubon's shearwater ("Puffinus lherminieri"). There are five listed subspecies of the tropical shearwater: The tropical shearwater is found in the tropical parts of the western Indian Ocean from east Africa to southern India and in similar regions of the Pacific from just to the southeast of Japan to French Polynesia. The total population has not been definitively quantified. Subspecies "P. b. dichrous" is estimated to number 1,000–10,000 pairs on the Line Islands and 10,000–100,000 pairs on the Phoenix Islands, with the nominate