Observations of ducks on Macquarie Island in December 1985 and 1986 are summarised. Although the island has many wetlands, previous records suggest that ducks mainly use those within wet tussock grasslands in the lowland, coastal areas: recent observations confirm this. Reduced primary productivity on plateau wetlands may result in minimal secondary production of foods in a relatively harsh environment, one where nesting cover has been degraded by introduced rabbits and where predatory skuas are prevalent. Ducks, including hybrids between grey duck and the alien mallard, used Square Lake and Duck Lagoon for feeding and resting, although their rate of feeding was higher at Square Lake. Broods were recorded only at Duck Lagoon, where Poa foliosa provides extensive cover. Introgression on Macquarie Island has occurred unsupported by local liberations, distant from human activity, and has implications for the gene pool of grey duck elsewhere.
Please note: This newsletter is a Supplement to Volume 34 (1) of Notornis, not a Supplement to Volume 54 (1) as shown on the cover page. We apologise for this error.
Four surveys for kokako were conducted in the Hunua Range between November 1986 and May 1988, by playing tapes of the local song dialect. Three of the four surveys were done in conjunction with the Auckland and South Auckland branches of the Ornithological Society of New Zealand. Forty kokako were recorded, of which 12 were definitely in pairs, one was a definite juvenile and another a possible juvenile. Some of the remaining 26 were likely to have been paired. Thirty-eight birds were recorded in tawa-podocarp forest and two in adjacent second-growth scrub. The 40 birds ranged in altitude between 300 and 660 m ad. with an average of 490 m. They were distributed in the following catchments: Mangatangi (20 birds), Mangatawi (12), Orere (5), Tapapakanga (2) and Hauarahi (1). Most records were of birds heard rather than seen, and tape responses were low compared with those in surveys elsewhere. Comparisons are made with past surveys and survey techniques, and the discussion includes options for forest management in the Hunua Range.
The osteology of the New Zealand genera Mohoua and Finschia shows that they are definitely not referable to the Pachycephalinae or any other group within the corvine assemblage. This is in contrast to Sibley and Ahlquist’s original interpretation of their DNA-DNA hybridization studies and supports a recent reanalysis of that data by critics, who concluded that these genera belong among the “Passerida”. Within that group, the relationships of Finschia and Mohoua remain uncertain. No osteological basis could be found for continuing to separate the genus Finschia from Mohoua. The three species in the expanded genus Mohoua show increasing specialization for use of the hindlimb in foraging and in order of most primitive to most derived should be listed as M. novaeseelandiae, M. albicilla, and M. ochrocephala. The last two species are very distinct from one another osteologically and are not to be regarded as subspecies of a single species.
Between April 1985 and March 1987, standardised shipboard censuses were conducted during 23 monthly transects from shore to well beyond the continental shelf. The average transect distance was 66 km and maximum depth 4200 m. Twelve (probably 13) species and 231 1 birds were recorded. Regular petrels (listed in descending percentage abundance) had zonal and seasonal distributions as follows: Pterodroma macroptera (50%), pelagic, spring and summer; P. solandri (24%), pelagic, autumn, winter and spring; Daption capense (16%), neritic, winter and spring; Macronectes spp. (5%), marginally neritic, winter and spring; small Pterodroma spp. (“Cookilaria”) (4%), pelagic, summer and autumn; P. lessonii (1%), pelagic, autumn, winter and spring. Petrels rarely observed were Fulmarus glacialoides (1), Pterodroma neglecta (3), Procellaria parkinsoni (4) and Pseudobulweria rostrata (1). Temperature preferences, morphological characters, behaviour and breeding status are discussed. The 200 + “Cookilaria” observed during two cruises in April 1985 may have been associated with a slope-water intrusion generated by the East Australian Current.
Mixed-species flocks of insectivorous birds were investigated at Kowhai Bush, Kaikoura, in monthly transect counts between July 1986 and June 1988. Four native species (brown creeper, silvereye, grey warbler and fantail) and two introduced species (chaffinch and redpoll) foraged in mixed flocks. Brown creepers and silvereyes appeared to behave as nuclear species by determining the direction of movement of mixed flocks. Mixed flocks were found throughout the day. The mean number of species per flock was 2.5 and the mean number of birds in flocks was 8.5. Mixed flocks were seasonal with none encountered during the main breeding period (Sep-Dec).
We give weights and measurements of 16 species of birds mist-netted in forest on Little Barrier Island, including 67 whiteheads (Mohoua albicilla) and 111 stitchbirds (Notiomystis cincta). The following criteria for distinguishing sexes were established. Female whiteheads weighed up to 15.9 g and males weighed 16.1 g or more. Most female stitchbirds had wings up to 92 mm long and most males had wings 95 mm or longer. Incidental observations of moult, ectoparasites and movements are recorded.
This study shows that the red-tailed tropicbird (Phaethon rubricauda) has a gradual clinal increase in the intensity of the rose-pink suffusion, egg size, culmen length and wing length in breeding populations between Kure Atoll in the northern Pacific and the Kermadec Islands in the southern Pacific. The illusion that birds from this cline comprise three subspecies has long been accepted because the large range of latitude that each subspecies had been arbitrarily given resulted in significant differences in mean measurements. However, as neither the northern rothschildi nor the southern roseotincta are clearly separable from melanorhynchos in the centre of the cline, they must all be one subspecies. Because the mean measurements of the nominate “subspecies” are nor significantly different from those of birds from
similar latitudes in the Pacific cline, or from westralis in the eastern Indian Ocean, there is no valid reason for distinguishing any subspecies in the red-tailed tropicbird.
Australasian bitterns (Botaurus stellaris poiciloptilus) were studied in the Whangamarino wetlands in the autumn and winter of 1986. A seasonal difference in the time of feeding was noted, as well as a local movement to feeding grounds. A decrease in the number of birds seen in the study area in winter seemed to be related to the duck hunting season and high water levels. A mixture of water purslane and willow weed on a wet substrate was the preferred habitat. “Surveillance posture” seems a better description of the traditional “freeze” behaviour. The birds gave this response even when there was no apparent danger.
New anatomical evidence shows that New Zealand’s extinct Stephens Island wren (Traversia lyalli Rothschild, 1894) had a much reduced wing skeleton, short, rounded, soft-quilled wings and an almost acarinate sternum. It was therefore the only known completely flightless passerine.