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
Galápagos shearwater white. It sometimes has a dark collar. Both sexes are alike, as are the young after fledging. It is a slender-bodied shearwater, about 29–31 cm long, with a wingspan of around 63 cm and weighs 123-225 g. The species closely resembles the tropical shearwater, although the latter is typically blacker and has a longer tail. The Galápagos shearwater is a gregarious species and will feed at sea with other shearwaters and boobies. It flies low over the water and feeds on squid, fish and offal. It intersperses 4-10 stiff wing beats with shallow glides. Galápagos shearwater The Galápagos shearwater ("Puffinus