Calonectris diomedea
Gwennap Head is part of the Porthgwarra to Pordenack Point Site of Special Scientific Interest (SSSI) designated for its vegetation of waved maritime heath, and for being of considerable ornithological interest; especially for passage migrants. It is renowned for its relative abundance of passing marine bird species with many common species such as northern gannet ("Morus bassanus"), Manx shearwater ("Puffinus puffinus"), common guillemot, ("Uria aalge"), razorbill ("Alca torda"), northern fulmar ("Fulmarus glacialis"), shag ("Phalacrocorax aristotelis") and cormorant ("Phalacrocorax carbo"). The headland is favoured by birdwatchers and many travel the length and breadth of Britain to track rare seabirds. In July and August there is a chance to see two large shearwater species outside of their breeding season. The great shearwater breeds in the south Atlantic on islands in the Tristan da Cunha group and the Cory's shearwater ("Calonectris diomedea") breeds in the Mediterranean, and on North Atlantic islands; mostly among the Azores. Many birds follow the coast as they migrate north in spring to breed or head south in the autumn to overwinter in warmer places.