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.
A re-examination of the moa genus Megalapteryx reveals that the two currently accepted species, M. didinus (Owen) and M. benhami Archey, do not differ in the shape of the bones. They represent small and large specimens in an unbroken size continuum. Specimens from northwest Nelson have a larger mean size than those in a sample from Takahe Valley, Fiordland. A series of 14C dates indicates that the largest ‘M. benhami‘ are all of Otiran derivation, whereas M. didinus bones are from Otiran and Holocene deposits. Therefore M. benhami is synonymised with the upland moa, M. didinus (Owen).
A colony of breeding Snow Petrels (Pagodroma nivea) in the Muhlig-Hofmann Mountains, Queen Maud Land, on the Antarctic continent was visited in January-February 1985. The birds were nesting under large boulders on the north-faced, ice-free hillside at Svarthamaren (71°53′ S,
5°1O’ E), about 200 km from the open sea. The colony was roughly estimated to contain 500 pairs (Mehlum et al. 1985). Hatching took place in mid-January. The Snow Petrels at Svarthamaren were on average significantly smaller than those breeding elsewhere in the Antarctic. The irregular geographical distribution of breeding birds of varying size does not immediately provide any support for a sub-specific division of the species into one large and one small form, leaving the systematic and evolutionary status of the species unclear. It remains to be established whether inland breeding selects for relatively small birds.