Origin, age, sex and breeding status of wandering albatrosses (Diomedea exulans), northern (Macronectes halli) and southern giant petrels (Macronectes giganteus) attending demersal longliners in Falkland Islands and Scotia Ridge waters, 2001–2005

A total of 547 sightings of 291 banded wandering albatrosses Diomedea exulans and 21 sightings of 14 banded giant petrels Macronectes spp. were made from toothfish longliners operating on the southern Patagonian Shelf during 2001–2005. This included 25% of the wandering albatrosses with Darvic bands that bred at Bird Island (South Georgia) during this period. Thirteen of the northern Macronectes halli and southern giant petrels Macronectes giganteus had been banded at South Georgia, and there was one sighting of a southern giant petrel from Argentina. Male and female wandering albatrosses of all age classes except young birds (<15 years old) were equally likely to attend longline vessels. Most sightings of all age classes were made during the incubation period and fewest during the brood period. Eighty-six percent of birds sighted had bred at least once before, with half currently breeding and half on sabbatical (i.e. between breeding attempts). Almost half of the wandering albatrosses were sighted on more than one occasion. The data confirms that the southern Patagonian shelf is an important foraging area for wandering albatrosses and northern and southern giant petrels, and that some individuals show consistent associations in multiple years with longline vessels fishing in the region.