Photographed 55 miles from shore.
This bird is very large maybe 40-50cm it was in a rocky bay next to Ushuaia, Argentina
juvenile (with White-capped Albatross)
the bird in the foreground
Several giant petrels were tailing the trawler along with all the smaller seabirds. Both Northern and Southern GPs were there; I couldn't tell them apart, since the difference has to do with some subtle difference in the bill tip color.
Both species were present in about equal numbers, though greatly outnumbered by White-chinned Petrels and Albatross.
The Southern Giant Petrel (Macronectes giganteus), also known as the Antarctic Giant Petrel, Giant Fulmar, Stinker, and Stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar Northern Giant Petrel, though it overall is centered slightly further south. Adults of the two species can be separated by the colour of their bill-tip: greenish in the Southern and reddish in the Northern.