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
Great shearwater can be seen in large numbers from ships or appropriate headlands. They have a piercing "eeyah" cry usually given when resting in groups on the water. Great shearwater The great shearwater ("Ardenna gravis"; formerly "Puffinus gravis") is a large shearwater in the seabird family Procellariidae. "Ardenna" was first used to refer to a seabird by Italian naturalist Ulisse Aldrovandi in 1603, and "gravis" is Latin for "heavy". The great shearwater's relationships are unclear. It belongs in the group of large species that have been separated as genus "Ardenna" (Penhallurick & Wink 2004); within these, it might be allied with the