Publications Archive

Observations from 15 years of voyages in coastal New Zealand waters are analysed. There is evidence for a continuing increase in numbers of Buller’s shearwater. The population pressure in northern waters is thought to be such that the extra birds are forced southwards to feed. The suggestion that the southern birds are non-breeders may be true but it is pointed out that as the total population increases so do the numbers of breeding birds which then have to forage further afield. Distribution maps showing seasonal movements and numbers including areas to the east and west of New Zealand are given. The three main feeding methods observed are described.

A study of habitat selection and feeding behaviour of brown teal (Anas castanea chlorotis) was conducted on Great Barrier Island from 7 to 14 February 1973. In the Port Fitzroy area, teal fed almost exclusively in the tidal estuaries. Feeding was tide-regulated. and foods seemed to be invertebrates selected on a declining tide. During high tide, teal usually roosted in the shade of trees. At several sites on the eastern part of the island, teal fed in slow-moving freshwater streams or brackish lagoons. In addition to dabbling and upending, teal dived regularly and efficiently. By a creek at Whangapoua Beach, most of 112 teal fed in the uplands either by probing in grass or by grabbing insect larvae from forbs. Teal also fed in the uplands at night. Brown teal are very adaptable in feeding sites and fill the niche of both aquatic dabbler and ground-feeder. They are most abundant in estuarine situations, and the survival of the species depends upon protection of suitable habitats. Intensive human use of estuaries on the mainland probably is responsible for the drastic decline of the species.

The grey heron (Ardea cinerea) was placed on the Suspense List of the 1970 OSNZ Checklist, as the Checklist Committee could not confirm the existence of an 1898 specimen reported by Buller. Buller’s “third collection,” including this heron, is in Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, U.S.A. The grey heron should be readmitted to the main New Zealand list, but under the name A. c. jouyi Clark rather than A. c. rectirostris Gould.

Subfossil and midden remains show the species was once distributed throughout the entire length of New Zealand and there seems little doubt that takahe were scattered throughout a much larger area of South Island during the latter half of the nineteenth century and in the early decades of this century than is generally known.

The often-told story of the antics of Adelie penguins fearful of entering water where leopard seals may be lurking is recounted and reinterpretations of this behaviour pattern are discussed. Few observations have been made of the methods used by the seals in capturing penguins and only one illustration of a ‘ near miss,’ a penguin that had escaped although with some injury, seems to have been published. Birds badly injured seen at Cape Adare in 1965 are illustrated and discussed in relation to the particular conditions at this site, the history and geographical setting of which is outlined. Accounts of predation by leopard seals, as given in the literature, are detailed and commented upon in the light of the casual observations at Cape Adare and of recent field work in the U.S. Antarctic Research Programme. Observations of such predation are shown to have been by good fortune rather than by deliberate intent. Physical conditions of ice, tides and local geography, as well as the numerical abundance of seals and the proximity of their breeding and foraging areas to the penguin rookeries are important but may vary in significance. The effect of leopard seal predation on the overall mortality of populations of both young and adult penguins is considered negligible in relation to the numerical size of their rookeries.

Sight records of the grey heron allegedly seen in New Zealand in 1947 and 1951 and recorded in the Classified Notes of the OSNZ are shown to be attributable to a youthful confusion with the white-faced heron (Ardea novaehollandiae) then less common than now. The background of this cautionary tale is given, resulting in the specimen of the grey heron in the Carnegie Museum of Natural History documented by Parkes (1974) representing the only genuine evidence of the occurrence of this species within the New Zealand Region. Following W.R.B. Oliver’s opinions expressed in his review of the first OSNZ checklist, some comments are made on the advisability of any checklist committee supporting its decisions on taxonomic or distributional changes by more detailed publications of its reasons. It is not considered sufficient to merge taxa or discard dubious records without documentation.

Details are given of the following evidence leading to an assessment of the number of takahe in the “Special Area,” a region of 518 sq. km in the Murchison Mountains: the number of known takahe ” territories ” in the various localities or areas of the Murchison Mountains from 1948 to 1971 inclusive; observations made by different organizations in the ” Special Area ” (excluding the Takahe Valley – Point Burn Study Area) since 1948; the substance of the observations on which the population estimate is based; details of field observations and estimates of total number of territories and total adult population in the ” Special Area ” during the 1960s. The total population of takahe is estimated to number about 435–510 with a possible maximum in excess of 560 birds.