Publications Archive - Page 104 of 243

Southern crested grebes on a lowland coastal lake in winter

Notornis, 35 (1), 75-76

C.F.J. O'Donnell (1988)

Article Type: Short Note

A Caspian Tern feeding on the ground

Notornis, 34 (2), 116

A.J. Middleton (1987)

Article Type: Short Note

A colony of the Little Shag and the Pied Shag in which the plumage forms of the Little shag freely interbreed

Notornis, 34 (1), 41-50

M.J. Taylor (1987)

Article Type: Paper

During the 1977-1985 period a colony of 80-120 Little Shags (Phalacrocorax melanoleucos brevirostris) was studied at Hobson Bay, Auckland City. The breeding season of Little Shags was from August to March or April. Pied Shags (Phalacrocorax varius), which joined the colony during the study period and have tended to displace the smaller species, have nested throughout the year. For both species highest numbers of nesting pairs were present in spring (October – November). Little Shags of the pied form constituted one-third of the colony and interbred freely with birds of the white-throated and smudgy plumages. Fledglings have either the pied or totally black plumage and both can occur within the same brood. Aspects of behaviour are described and a detailed account of the colony is given.

Notes on the birds, reptiles and mammals of Tongatapu and ‘Eua (Tonga)

Notornis, 34 (3), 217-223

B.J. Gill (1987)

Article Type: Paper

During 13 days on Tongatapu and 9 days on ‘Eua (Kingdom of Tonga) I noted 16 and 20 species of birds respectively. I collected 5 species of reptile on Tongatapu and 3 on ‘Eua. Two species of ectoparasite from a Polynesian rat (Rattus exulans) were identified.

Unexpected reaction of Bar-tailed godwits to a rain squall

Notornis, 34 (1), 84

D.E. Widgery (1987)

Article Type: Short Note

Changes in gull numbers over 25 years and notes on other birds of the Otaki-Ohau Coast

Notornis, 34 (4), 327-338

R.G. Powlesland, H.A. Robertson (1987)

Article Type: Paper

The number of Black-backed Gulls (Larus dominicanus) between the Otaki and Ohau Rivers, on the southwest coast of the North Island, has more than doubled in the last 25 years. There was a significantly larger proportion of subadults in 1961 than now, indicating that the population may have been in a growth phase in the early 1960s. The number of Red-billed Gulls (L. novaehollandiae) was about one-third of the 1961 level; this coincides with a sharp fall in the number of Red-billed Gulls nesting on nearby Kapiti Island. Numbers of other coastal birds were recorded and are discussed.

Classified Summarised Notes, North Island, 1 July 1985 to 30 June 1986

Notornis, 34 (2), 117-147

L. Howell (1987)

Article Type: Paper

Genetics of polymorphism in the Little Shag

Notornis, 34 (1), 51-57

J.E. Dowding, M.J. Taylor (1987)

Article Type: Paper

A genetic model is presented to explain plumage polymorphism in the Little Shag (Phalacrocorax melanoleucos brevirostris). Parent-offspring data from an Auckland colony show that expression of the three morphs (white-throated, smudgy and pied) is primarily controlled by two alleles at a single genetic locus. The allele specifying ‘dark’ (D) shows incomplete dominance over that specifying ‘pied’ (6). Comparison of morph frequencies with calculated genotype frequencies reveals that about 40% of white-throated birds are homozygous dominant (DD), the rest of the white-throated birds and all smudgy birds are heterozygous (Dd), and pied birds are homozygous recessive (dd). The population mates non-assortively and the Hardy-Weinberg law correctly predicts the frequencies of black and pied offspring from crosses. Morph frequencies (and allele ratios) show a gradient from north to south in New Zealand, dark birds being more common in the south. The main factor maintaining this cline may be climatic.