Publications Archive

We assessed the numbers, distribution, and habitat of Bristle-tithed Curlews (Numinous tahitiensis) on Rangiroa Atoll, Tuamotu Archipelago, during a visit in April 1988. We estimated a total of 250-350 curlews on the atoll. These birds were seen only on the southern and western rims, where they were most common on (1) saltpans within clusters of small islets and (2) narrow channels between islets that were bordered by shrubs and herb mats. The distribution of curlews on Rangiroa appeared to be determined by the distribution of humans and their commensal animals and by the availability of habitats. Given the species’ relatively low numbers, low reproductive rate, and prebasic moult which, for some adults, entails a flightless period, conservation and management efforts must begin on the non-breeding grounds. These efforts should focus on reducing or eliminating potential mortality factors such as subsistence harvest, introduced predators, and contaminants. Countries throughout the species’ non-breeding range are encouraged to be active in these efforts.

In a 20-year nest box study of Starlings (Sturnus vulgaris) in New Zealand, intraspecific fighting was the main mortality factor recorded. All fights were between birds of the same sex, 24 male-male and 22 female-female, and most were in the breeding season. Fighting increased as the population rose from about 300 birds in 1969 to over 3000 after 1978. Because of the low annual mortality rate of Starlings in New Zealand (330/0), the chances of ever breeding were small for many birds. Hence conditions were ideal for a high level of fatal fighting, which took the form of grasping the opponent round the head so that the claws penetrated the brain through the eye sockets.

Changes in cock Pheasant calling frequency during the breeding season were measured for two Wanganui Pheasant populations between 1986 and 1988 by recording counts at 2-week intervals during the period September to December. Calling intensity varied considerably between successive 2-week intervals. It reached a peak during mid-November but was much less by late December. To estimate variability between successive counts, call counts were recorded in six areas along the Wanganui-Manawatu coast between 6 and 11 November 1988. Within site variance averaged 25% of total variance between and within study sites.

From 13 to 17 August 1990, we surveyed from Doubtful to Milford Sounds, Fiordland, for Fiordland Crested Penguins. Minimum total estimates were 65 nests and 283 penguins. Proper counts were not made at a few sites and some small breeding groups were probably missed, but we are confident that all major breeding sites in the survey area were located. These penguins breed primarily in small isolated colonies on islands, or in small caves on the mainland coastline. The largest breeding site in the survey area was on the Shelter Islands, at the entrance to Doubtful Sound. Most nests were in dugouts under trees or on small ledges under rocky overhangs. A few penguins were breeding on islands up to 30 km from the open sea. We tentatively propose that there are less than 1000 nests for the species annually.

The islands of ‘Ata and Late have been visited for the first time by an ornithologist. The islands are important breeding sites for seabirds. Fregata ariel and F. minor nest on both islands. ‘Ata is the only Tongan island where Sula serrator dactylatra breeds. It also has a large population of Puffinus pacificus, and a few Procelsterna cerulea have been seen. Among forest birds, the abundance of Gallicolumba stairii on Late was most conspicuous. Among the rare and locally distributed birds of Tonga, the whistler Pachycephala melanops and the fruit-dove Ptilinopus perousii were found to be common. The lory Vini australis was seen only occasionally. On Niuafo’ou, Jungle Mynas Acridotheres fuscus have increased dramatically since 1984; the species is now considered a pest on fruit crops. The megapode Megapodius pritchardii seems to be threatened not only by the collecting of eggs, but also by development plans of the Tongan government. Numbers are probably higher than estimated in 1984. The avifaunal history of the three islands is discussed in the light of recent palaeontological findings. Human activities probably had a significant influence on the present-day composition of fauna and flora. The avifauna of Late probably comes close to that of a young volcanic island in pre-human times and so offers great chances for comparative studies in avian ecology. Finally, conservation issues are discussed, stressing the importance of remote Tongan islands for a regional concept of bird preservation.

Radio-tagging of 54 New Zealand Pigeons (Hemiphaga novaeseelandiae) captured at Pelorus Bridge Scenic Reserve, Marlborough, showed that about half of the birds which fed there in spring on deciduous foliage moved away from the reserve from early summer onwards. They travelled 2-18 km to other areas of native forest. Most remained away for 2-9 months and at least some bred at their summer destinations. Individual birds tracked in different years provided strong evidence for their using traditional seasonal ranges, although the timing of movements varied between years, depending on fruiting phenology and breeding success. Some birds made up to three return movements from and back to Pelorus Bridge within a year, visiting different destinations in different seasons. Late summer and autumn movements were apparently linked to feeding on miro (Prumnopitys ferruginea) fruit. Five of 25 radio-tagged pigeons which moved to known destinations away from the reserve occupied areas of privately owned native forest during the breeding season.