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
Persian shearwater off Oman and Socotra, Yemen, while "P. p. temptator" has been estimated to number fewer than 500 pairs on Moheli Island in the Comoros (reviewed by Brooke 2004). It is thought likely that more breeding colonies lie undiscovered elsewhere in the northern Indian Ocean (Onley and Scofield 2007), thus the total population probably includes more than 10,000 mature individuals. The population trend is believed to be downwards. Persian shearwater The Persian shearwater ("Puffinus persicus") is a seabird in the family Procellariidae formerly lumped in with Audubon's shearwater ("Puffinus lherminieri"). There are two listed subspecies of the Persian shearwater: After breeding,