Publications Archive

Obituary, pages 179 to 186. Bibliography, pages 187 to 195.

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. Footnote 1.  This is the New Zealand nomenclature. The author prefers to call the form involved the Subantarctic skua (Catharacta antarctica lonnbergi).

Between 8 November and 4 December 1978 observations were made on Southern Great Skuas (Stercorarius skua lonnbergi) at Antipodes Island in the Southern Ocean. Their food habits were determined by observing birds and identifying prey remains. Penguin eggs and chicks were the dominant prey of coastal skuas, whereas those with inland territories relied on petrels and shearwaters. Clutch size in 11 nests averaged 1.8 eggs; most eggs in nine study nests hatched during the first fortnight of November. Hatching success was 54%, but only 3 of 10 chicks survived until 4 December. At that stage of the breeding season, and allowing for unnatural losses of eggs and chicks, productivity was 0.5 chicks per breeding pair. Six chicks were weighed and measured for 5-20 days. Hatching weight averaged 74.3 g. Initial weight gains were small, but after day 4 the average growth rate was 31.6 g/day. Chicks which were heavier at hatching remained so subsequently. Mean bill length at hatching was 17.8 mm and mean depth 9.9 mm. Little growth occurred for the first five days, but afterwards the average growth rate was 1.0 mm/day for bill length and 0.4 mm/day for bill depth. The ratio of bill length to depth changed during growth, and attained the adult condition by age 17-20 days. There were no consistent differences between chicks from coastal and inland nests in their weight gains, or in the growth of their bills.

Contributors: Stanely Cramp (chief editor), K. E. L. Simmons, I. J . Ferguson-Lees, R. Gillmor, P. A. D. Hollom, R. Hudson, E. M. Nicholson, M. A. Ogilvie, P. J. S. Olney, K. H. Voous, J. Wattel. Volume 1: Ostrich to Ducks. 722 pp. 108 col. pl. Oxford University Press 1977.