The 'Mollymawk' Albatross are in the genus Thalassarche. They are smaller than the Great Diomedea Albatross. Unlike the latter birds, the Mollymawks have a dark back. The different species in the genus can usually be distinguished from each other by their slightly different coloured bills.
Black-browed Mollymawk, view of upperside
Black-browed Mollymawk, view of underside
Southern Giant Petrel
Pachyptila belcheri, 'Slender-billed Prion' (between Ushuaia and Falklands). Long thin bill, large white eyebrow.
Pachyptila desolata, 'Antarctic Prion' (Scotia Sea).
Wilsons Storm Petrel