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
Summerland Peninsula Bird Area. It is home to one of the largest Little Penguin ("Eudyptula minor") breeding colonies in Australia, the second largest breeding colony of Australian Fur Seals ("Arctocephalus pusillus doriferus") in the world, one of the largest breeding colonies of Greater crested terns ("Sterna bergii") in Victoria and an important breeding ground for Short-tailed shearwaters ("Puffinus tenuirostris"). Several plants regarded as rare or threatened in either Victoria or Australia have been recorded on the peninsula, including River Swamp Wallaby-grass ("Amphibromus fluitans") listed as vulnerable in Australia. The peninsula was significantly modified by agricultural, residential and recreational developments until the 1980s