Timing of breeding, breeding success and chick growth in South Polar Skuas ( Catharacta maccormicki ) in the eastern Larsemann hills, Princess Elizabeth Land, East Antarctica | Notornis and Birds New Zealand

[摘要] Details are given of the breeding phenology, breeding success and growth of chicks, obtained during the 1989/90 summer in a small population of South Polar Skuas nesting in the Larsemann Hills (69021°S, 76003°E), Princess Elizabeth Land, east Antarctica. Eggs were laid from mid-November to mid- December (mean date 30 November), chicks hatched from mid-December to early January (mean date 26 December) and fledged from 5 February onwards (mean date 16 February). Breeding success in the 13 regularly monitored nests averaged 0.5 chicks fledged per pair, i.e. 0.26 per egg laid. Asynchronous hatching resulted in most first chicks (from first eggs) dominating their siblings; they grew faster and survived better than the second chicks, presumably as the result of more food. Second eggs were significantly smaller than first eggs, and egg size and volume gave rise to slight differences in mass at hatching; this did not appear to influence chick growth. Food availability, unfavourable weather conditions and predation by other skuas were the main factors influencing chick growth and successful chick rearing; the presence of sibling aggression may have reduced survival in second chicks. Breeding success in the Larsemann Hills is considered in relation to foods available from feeding territories or from station refuse; in the small samples available, those pairs with obvious territories or with amore chicks to the flying stage.

[学科分类] 动物科学

[关键词] Black-fronted Dotterel;Charadrius melanops;New Zealand;population;Wairarapa