The distribution of Banded Rails and Marsh Crakes in coastal Nelson, Buller and the Marlborough Sounds was surveyed between October 1980 and December 1982. Banded Rails and Marsh Crakes were found only in saltmarshes in Nelson and the Marlborough Sounds, though Marsh Crakes were difficult to detect and could have been more widespread. Banded Rails were found only in saltmarshes with a freshwater supply with stands of sea rush and mixed stands of jointed rush and marsh ribbonwood. The Nelson – Marlborough Banded Rail population consisted of about 100 breeding pairs and is isolated from the Banded Rail populations further north and south.
Birds in forest in the Orongorongo Valley near Wellington were caught over a 7-year period (1969-76) in mist-net rigs consisting of six nets one above another, forming a continuous curtain of nets from near ground level to the
forest canopy. We recorded which net in the rigs each bird was caught in, and described the vertical distribution of 14 species of bird. Hedgesparrows, Fantails, Tomtits and Blackbirds were caught more often in the lower nets,
Kingfishers, Silvereyes and Bellbirds were caught more often in the upper nets, and Moreporks, Riflemen, Whiteheads, Grey Warblers, Song Thrushes, Tuis and Chaffinches were caught more or less evenly at both levels. The vertical profiles differed between rigs. For the three species caught most commonly (Silvereye, Blackbird and Bellbird), the mean height of capture varied with time of day and with season. The vertical distribution is a useful characteristic in helping to define the niches of these birds.
Harrier diet and population dynamics were studied at Tekapo River in 1985 and 1986, and stomach contents were analysed from 239 specimens collected in the Cass Valley in 1983-85. Harriers in both study areas fed mainly on rabbits, including young live rabbits and carrion. Local changes in rabbit abundance led to changes in the distribution and numbers of harriers. Immature harriers were mainly transients and responded to changes in rabbit numbers more than adults did. When rabbits were scarce, the resident harriers fed more on alternative prey. such as skinks, but there was no corresponding increase in the numbers of birds eaten. Males fed on alternative prey more than females did. Males were outnumbered by females in the study area with lower prey diversity.
In 1986, 4,594 kilometres of coast were patrolled and 14,462 dead seabirds were found. Three new species for the Beach Patrol Scheme were the White-naped Petrel (Pterodroma cervicalis), the White-capped Noddy (Anous minutus) and the White Tern (Gygis alba). Four species found in greater numbers in 1986 than previously were the Yellow-nosed Mollymawk (Diomedea chlororhynchus), Narrow-billed Prion (Pachyptila belcheri), Short-tailed Shearwater (Puffinus tenuirostris) and Stewart Island Shag (Leucocarbo carunculatus chalconotus). A summary is given of the coastal and monthly distributions for each species of Pachyptila found between 1960 and 1986. The Fairy Prion (P. turtur), a New Zealand resident, was found most frequently mainly in February and between July and November. By comparison, the other five species, all migrants to New Zealand, were picked up mainly during July-August.
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 By. Sight recoveries of juveniles indicated that those which had fledged early or midway through the season subsequently migrated to Australia bur 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.