Publications Archive

Results are given of a census made in August 1977 of cattle egret and other egrets, spoonbills and ibises in New Zealand. Approximately 300 cattle egrets were present. The year’s records are given for each region, together with observations on plumage and habits. Features of cattle egret distribution and plumage changes are discussed.

Descriptions, distribution, banding data and details of nesting seabirds are given for various islands within the Fiji group visited during 1974, 1975 and 1976. These include Vatu-i-Ra, Vatu Lami, Yabu Is., Mabulau, Nuku-i-Cikobia, Sovu, Cikobia-i-Lau, Qilaqila, Lakeba, Nanuku Levu, Nanuku Lailai and Nasautabu. Species found nesting were red-footed, masked and brown boobies, lesser frigate bird, white-tailed tropic bird, reef heron, black-naped, sooty, bridled and crested terns, common and white-capped noddies.

This is a complete list of species and subspecies recorded from the Fiji archipelago subsequent to the work of Mayr (1945), Mercer (1966) and King (1967). Some of these new records have been published previously, but fifteen new specific and sub-specific records of birds are listed here together with a new breeding record and confirmation of some earlier doubtful sightings.

The breeding and habits of the Antarctic tern (Sterna vittata) were studied during a summer at the Snares Islands. Daily records were kept of ten nests situated on cliff ledges and rocks. Egg-laying occurred during two periods; late October/early November and late November. The usual clutch was one egg, but some two-egg clutches were laid. Re-laying probably occurred on one occasion when the first clutch was lost. Both parents incubated, and the incubation period averaged 24 days. The chicks were guarded for two to three days after hatching and were fed by both parents. Chicks fledged between 27 and 32 days after hatching. Adverse weather severely restricted chick growth during the early stages of development and was a major factor in chick mortality.

Data on the distribution of the New Zealand falcon were collected from all likely sources and from field studies in five areas. The known status of the falcon is given and is summarised in two distribution maps. The entire population is estimated using known densities in study areas. About 3100–3200 pairs of “eastern falcons,” 450–850 pairs of “bush falcons” and 140–280 pairs of “southern falcons ” (total about 3700–4350 pairs) may exist. Probably 3000–4500 pairs is a realistic estimate of the falcon population; 2000 pairs at the least.

Factors causing predation of the clam paphies (Mesodesma ventricosa), the well-known ” toheroa,” by black-backed gulls are described. Counts of black-backed gulls made at approximately monthly intervals along a 23 kilometre stretch of beach between January 1970 and January 1971 and in December 1972, together with further observations between 1968 and 1975 show that black-backed gulls are important predators of toheroa.

Birds were counted in four forest areas every second month of a year to determine broad habitat preferences of the different species and the factors affecting the numbers counted. Most species showed marked seasonal changes in conspicuousness. The differences between the numbers of birds counted by different observers were generally small compared with the differences between areas and seasons. Many species were more abundant in the valley-bottom forest than in the two hill-country forests; only a few species preferred high-altitude forest. The preferred habitat of some species changed with season. The implications of these findings for bird conservation in Westland forests are discussed.

Results are given of a monthly survey of birdlife in the subalpine Lake Harris basin, north-west Otago Alps. Fluctuations over a year, from May 1976 to April 1977, were tallied by species and by numbers of individuals. Comments are made on effects of climatic conditions and resources available to birds at such altitudes in the Southern Alps along the Main Divide. Arising from observations made so far, it is suggested that the rock wren (Xenicus gilviventris) may hibernate during harsh winter months.

During 1976, 2,826 kilometres of coast were patrolled by 151 members of the Ornithological Society of New Zealand and their friends. 5,990 dead seabirds were found. There were no major wrecks. A number of minor wrecks involving blue penguins (Eudyptula minor), white-headed petrels (Pterodroma lessoni), sooty shearwaters (Puffinus griseus) and fairy prions (Pachyptila turtur) are recorded. White-faced storm petrels (Pelagodroma marina) were found in higher numbers than ever before particularly on Canterbury South beaches. Patrols of Mason’s Bay, Stewart Island, were the major factor contributing to the highest ever total of mottled petrels (Pterodroma inexpectata). The grey ternlet (Procelsterna cerulea) found is a second record and the black-fronted tern (Chlidonias hybrida) a new record for beach patrolling. The Christmas Island shearwater (Puffinus nativitatis) found is a new record for the New Zealand region.