Four species of Pterodroma petrel (P. macroptera, P. cervicalis, P. pycrofti and P. nigrippenis) responded strongly to human calls (termed by us the “war-whoop” method). This response was greater in the larger species and included the following behaviour: more frequent calling, movement towards the observer, and fighting. The level of response in P. macroptera was greatest during courtship and incubation and decreased during the chick rearing stage. Our findings support Warham’s (1988) hypothesis that mainly unpaired birds respond to human calls and that the birds associate these sounds with sexual advertisement.
Attempts to re-establish Wekas, Brown Kiwis and Red-crowned Parakeets in the Waitakere Ranges were made between 1976 and 1986. None appears to have been successful, although Wekas did breed at Huia for several seasons.
Cavity nesting by Stitchbirds (Notiomystis cincta) was studied on Little Barrier Island by adding artificial nest sites (boxes) in a breeding habitat. The addition of boxes was a test of the theory that the number of breeding pairs of cavity nesting species is limited by the availability of suitable holes for nest sites. Site limitation is also said to prevent males of these species from taking more than one mate. This theory was tested by placing some boxes close to natural nest sites and other boxes. Results showed that the number of breeding Stitchbirds was not necessarily limited by the availability of sites, and that lack of sites did not restrict male birds to monogamy. The boxes could be a useful management tool for enhancing this rare species.
The effect of wind and sea conditions on the feeding of Antarctic Terns (Sterna vittata bethunei) was studied during three visits to the Snares Islands. The terns preyed upon fish and swarms of crustaceans. Increasing wind speed significantly reduced the terns’ capture rate and feeding success. The terns fed in similar ways with calm and moderate seas. However, rough seas significantly reduced the attempt rare, capture rate, and feeding success of terns feeding on fish and the capture rate and success of terns feeding on crustaceans. Foraging techniques varied with the type of prey sought and
sea conditions. To catch fish, the terns mostly plunge dived in calm seas but contact dipped for 40-46% of attempts in moderate and rough seas. They caught crustaceans mainly by contact dipping, but used partial plunge diving more in moderate and rough seas. Wind speed and sea conditions seemed to affect terns feeding on crustaceans by making prey move away from the surface. Several other species of seabirds joined the terns to feed on crustacean swarms. Interspecific interactions were minor; however, large flocks of Sooty Shearwaters (Puffinus griseus) displaced terns from feeding on swarms.
From April 1987 to April 1988 (inclusive) I completed 195 5-min stationary bird counts at two forested sires in the Auckland City Domain. Auckland Domain has 22 species of passerines and near-passerines, more than half of them introduced. The mean annual counts – the first published for the North Island – showed a very high incidence of Silvereyes, Blackbirds and Fantails compared
with beech-podocarp forests and conifer plantations of the northern South Island, and a low incidence of Grey Warblers and Shining Cuckoos. Whether these are general characteristics of northern or urban forests awaits further study.
The breeding of the Grey-backed Storm Petrel (Garrodia nereis) at Houruakopara Island in the Chatham Islands (44° 06′ S, 176° 31′ W) was investigated and the nest site, egg, and chick are described. Both parents incubated the egg in poorly synchronised shifts averaging 1.9 days. generally followed by a desertion period of 2.7 days. Eggs hatched from mid-November, and the chick was brooded by either parent for up to 4 days after hatching. Chicks were fed on average every 1.6 days and the size of each feeding increased with age. The average daily increase in body weight was 12.6%, and by 17 days the
weight of the chicks equalled that of the adults.
Evidence of competition for nest sites within the species and with Broadbilled Prions (Pachyptila vittata) and Little Blue Penguins (Eudyptula minor) is discussed and a list of food items taken from regurgitations is presented.
The vertical and horizontal zonation and foraging habits of 17 Fijian forest passerines are described. Mist-netting showed that five species, Island Thrush, Fiji Shrikebill, Blue-crested Broadbill, Spotted Fantail and Orangebreasted Honeyeater, contributed to 60% of the captures. These were the five main lower-zone species on Viti Levu, but only two and three on Vanua Levu and Taveuni, respectively, where other species occupied this zone.
The species foraging in the middle and upper zones were more similar between the islands with two species of White-eye, two or three species of honeyeater, Polynesian Starling and Vanikoro Broadbill predominating. Horizontal zonation showed that most species occupied the middle and outer zones, except for the Fiji Shrikebill. Foraging strategies revealed that the
Spotted Fantail and the Vanikoro Broadbill were the main flycatchers, followed by the Golden Whistler and Slaty Flycatcher. The main gleaning species were the Fiji Shrikebill and the Silktail, most other species being foliage-searchers.