A small proportion of Southern Great Skua (Stercorarius skua lonnbergi’
) nests at Marion Island (46″54’S 37″45’E) are attended by three adults – a trio. The contents of the trio-attended nests and the growth of the three trio-attended chicks were studied in comparison with the contents of 16 nests and the growth of 23 chicks, attended by two adults. Eggs at two of the trio nests were laid exceptionally late in the season. No other difference in nest contents was found. Trio-attended chicks grew faster and probably attained independence with more substantial body reserves than chicks attended by two adults.
. This is the New Zealand nomenclature. The author prefers to call the form involved the Subantarctic Skua (Catharacta antarctica lonnbergi