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
Bulweria "b" sequence analysis has proven them to be closely related to the shearwaters in the genus "Puffinus" and especially the "Procellaria" petrels. Bulweria Bulweria is a genus of seabirds in the family Procellariidae named after English naturalist James Bulwer. The genus has two extant species, Bulwer's petrel ("B. bulwerii") and Jouanin's petrel ("B. fallax"). A third species, the Olson's petrel ("Bulweria bifax"), became extinct in the early 16th century; it is known only from skeletal remains. Bulwer's Petrel ranges in the Atlantic, Indian and Pacific Oceans, whereas Joaunin's Petrel is confined to the northwestern Indian Ocean. Olson's Petrel is known