Publications Archive

A communal roost of the Australasian harrier was studied at Huntly from late January to early April 1975. The roost was situated in standing hay and extended over about 0.36 of a hectare. Most individual roosts were found clustered in groups among the most dense vegetation. Morning and evening observations showed that a consistent pattern of movement was followed. A limited amount of aerial displaying was also observed. Previously, it has been suggested that communal roosts occur when harriers gather to exploit a local food abundance. Evidence gathered from the Huntly roost indicates that this contention may not be true for all roosts.

Comfort movements of the parrot Nestor notabilis in captivity are described and their occurrences in sequence statistically analysed. Some movements were found to be significantly associated.

South Island robins (Petroica australis australis) have frontal spots of white feathers which can be moved independently of other contour plumage to produce sudden visual contrasts. There are differences in the degree to which either the spot or the crown feathers are displayed. Display of the spot is most often interspecific or given by a lone bird, whereas raising the crown feathers usually occurs in intraspecific contexts. Details of each display are described. Crown elevation seems to function as an advertisement of aggressive levels to other robins, and, therefore, its function seems to me more specific than described for other passerines. Display of the spot is seen in response to several threatening or alarming situations, showing some of the characteristics of display of the crown or crest in other passerines. Its function in advertisement of escape or submissive motivation is clear in most intraspecific contexts, but outwardly, display of the spot in interspecific context shows strong aggressive elements. Display of the frontal spot is discussed in relation to function and evolution in other Petroica species.

During the period 25 April to 5 July 1974 observations were made of the numbers and direction of Westland black petrels overflying the coastal road at points between Perpendicular Point (3 km north of Punakaiki) and Barrytown (16 km south of Punakaiki), north Westland, to determine the area used for breeding. Intensive searches of known breeding areas and areas to which birds were seen flying were then made and the distribution and numbers of burrows mapped.

Observations on Sterna vittata and S. virgata breeding and foraging at Marion Island are reported. The breeding season of S. vittata corresponds with the period of least strong wind. The breeding periodicity of S. virgata is apparently less affected by seasonal wind variation, since the bird obtains much of its prey on land.