Since its recent arrival in New Zealand the black-fronted dotterel (Charadrius melanops) has begun winter flocking, and a newly observed feeding technique has become common. This new feeding behaviour is used mainly on hard substrate. The bird taps the substrate before pecking at prey, and on hard substrate the capture rate is higher than by simple pecking. By imitating the tapping on soft, intermediate and hard surfaces, I found that vibrations from the tapping on hard substrate alone caused flies to jump, making them more visible. In winter, birds were heard calling an hour before sunrise as they flew from sleeping sites scattered along the Manawatu River to the sludge ponds at the freezing works. The dotterels returned to the river after several hours of feeding but again visited the sludge ponds from mid-afternoon to almost an hour after sunset. At both the river and the sludge ponds most prey consisted of two species of fly. Daily time budgets showed that birds were feeding for 38% of the day while incubating, 69% while tending chicks and 86% during a winter’s day. It was estimated that during a winter’s day, one apparently normal bird caught 28,737 insects. To do this it pecked at 31,579 insects and caught one insect every 1.5 seconds.
The breeding of banded dotterels (Charadrius bicinctus) was studied in 1977-1987 at Cass River Delta, Lake Tekapo. Most birds first nested as 1-year-olds, but 1-year-olds arrived later on the breeding grounds than experienced adults. Nest site fidelity between years was high for experienced males but less for experienced females. Natal site fidelity was lower in females, which nested up to 31 km from the natal site. The birds were monogamous and usually retained the same mate for repeat clutches within a season, but most changed mates between years. Family members parted at about the time the young could fly. Sight recoveries of juveniles indicated that those which had fledged early or midway through the season subsequently migrated to Australia but late-fledging juveniles were non-migratory.
A new species of extinct starling, Aplonis diluvialis, is described from the Fa’ahia Archaeological Site on Huahine, Society Islands, French Polynesia. A. diluvialis was larger than any Indo-Pacific congeners except A. atrifusca of Samoa. The only other eastern Polynesian islands where starlings have been recorded with certainty are Rarotonga (A. cinerascens) and Mauke (A. mavornata). In pre-human times, however, species of Aplonis may have occurred through much of eastern Polynesia.
Discriminant function analysis was used to calculate classification formulae for predicting the sex of 98 adult grey-faced petrels (Pterodroma macroptera gouldi) at the start of incubation. Body weight, bill length, bill width, and bill depth all showed statistically significant sexual dimorphism. A classification formula based solely on bill measurements is impractical for sexing grey-faced petrels because of 37% error. The combination of body weight and bill depth in the formula proved useful, correctly classifying 92% of birds. This method provides a simple and reliable way of sexing grey-faced petrels in the field just after laying. Cloacal examination also allows definitive sexing at this time.
A re-examination of the moa genus Megalapteryx reveals that the two currently accepted species, M. didinus (Owen) and M. benhami Archey, do not differ in the shape of the bones. They represent small and large specimens in an unbroken size continuum. Specimens from northwest Nelson have a larger mean size than those in a sample from Takahe Valley, Fiordland. A series of 14C dates indicates that the largest ‘M. benhami‘ are all of Otiran derivation, whereas M. didinus bones are from Otiran and Holocene deposits. Therefore M. benhami is synonymised with the upland moa, M. didinus (Owen).