Publications Archive

Between 1987 and 1996, 2,383 Wrybills (Anarhynchus frontalis) were banded on their wintering grounds at two locations near Auckland; 690 of these were recaptured on 830 occasions. Birds started to arrive at their wintering grounds in December; and stayed at the more northern location until April, when they moved to wintering sites further south. First year birds comprised

The Westland Petrel (Procellaria westlandica) population is thought to have increased significantly in recent decades, perhaps as a result of increased food in the form of waste from fishing vessels. A survey of Westland Petrels off the West Coast of the South Island, New Zealand, showed that fishing vessels in the West Coast South Island Hoki (Macruronus novaezelandiae) fishery influence the distribution of Westland Petrels, but only a small proportion of the Westland Petrel population appears to utilise this fishery waste at any one time. Westland Petrels appear to select foraging areas primarily on natural features, such as water depth, and only if fishing vessels are in the same area are Westland Petrels attracted to them.

Morphological comparison of the extinct Huia (Heteralocha acutirostris) with its closest known relatives suggests that the pronounced sexual bill dimorphism of the former evolved through selection on female, rather than male bill form. Because sexual selection acts predominantly on males, it cannot readily explain such dimorphism in a non-polyandrous species. Greater female divergence in foraging-related anatomy in a species in which males are the larger (and therefore presumably socially dominant) sex is, however, consistent with the hypothesis that sexual dimorphism can be an adaptation to reduce intersexual competition for food. Determining which sex changed most is a more rigorous means of establishing the evolutionary significance of sexually dimorphic traits than interpretation of current function.

Measurements of the lengths of fossil bones show that North Island Laughing Owls were appreciably smaller than South Island ones. Humeri and tarsometatarsi from the North Island were on average significantly shorter than those from the South Island. The regressions of humerus length and tarsometatarsus length on latitude were significant, and length and latitude were positively correlated. The North Island samples were too small to establish whether variation was clinal, and in the meantime the continued recognition of North and South Island subspecies seems warranted. KEYWORDS: Laughing Owl, Sceloglaux, fossil bones, geographical variation, subspecies.

Evidence of predation by kiore (Rattus exulans) on Little Shearwater (Puffinus assimilis haurakiensis) eggs was obtained on Lady Alice Island, Hen and Chickens Group, during the 1994 breeding season. A time-lapse video camera filmed a kiore removing a Little Shearwater egg from a nesting chamber. This egg was later recovered, showing signs of damage typical of rat predation. A kiore was also filmed breaking open and eating a punctured hen egg that had been placed in a shearwater burrow. Sixteen (55%) of the 29 nests monitored failed during incubation, and predation by kiore was the probable cause of failure for up to 75% of these nests.

Records of all mollymawk sightings on Bollons Island, Antipodes Islands, are reviewed. Data are provided to confirm the breeding record for Black-browed Mollymawk Diomedea melanophrys melanophrys and add a new breeding record for the NZ White-capped (Shy) Mollymawk Diomedea cauta steadi.