Long-tailed cuckoos (Eudynamys taitensis) were studied on Little Barrier Island during three summers. The only species of host was the Whitehead (Mohoua albicilla). Rates of brood parasitism on the island were 18.1% overall, 35.7% at altitudes above 250 m, and 5.4%
at altitudes below 250 m. The breeding season for cuckoos probably lasted for 4-6 weeks from mid-November, suggesting that early nests of the Whitehead escaped brood parasitism. The available information
suggests that the major hosts of the cuckoo are the Whitehead, the Yellowhead, and possibly the Brown Creeper, although other hosts are used occasionally. As adult cuckoos call in small groups during the breeding season, I speculate that Long-tailed cuckoos may have
a lek-type social organisation.
In 1985, 5,967 kilometres of coast were patrolled and 28,304 dead seabirds were found, both new records for the Beach Patrol Scheme. A new species for the Scheme was a White-bellied Storm Petrel (Fregetta grallaria). Ten
species were found in greater numbers in 1985 than in any previous year: Little Blue Penguin (Eudyptula minor), Buller’s Mollymawk (Diomedea bulleri), White-headed Petrel (Pterodroma lessonii), Fairy Prion (Pachyptila turtur), Fulmar Prion (P. crassirostris). Fluttering Shearwater (Puffinus gavia), Australasian Gannet (Sula bassana), Pied Shag (Phalacrocorax varius), Redbilled Gull (Larus novaehollandiae scopulinus) and White-fronted Tern (Sterna striata). The record numbers of Fairy Prions, Fulmar Prions and Fluttering Shearwaters were the result of wrecks of these species in August-September, mainly along the western and southern coasts of the North Island. A summary is given of the coastal and monthly distributions for most Pterodroma species found during the 1960-1984 period. The most frequently found species was the White-headed Petrel, a result of 30-100 being found in spring of most years.
Intraspecific variation in morphometrics, plumage colouration, moult and breeding is described and its taxonomic significance assessed. There is a latitudinal cline in morphometrics and colouration among mainland, nearshore island, and Auckland Is populations. Southern bellbirds are larger and more brightly coloured, but they have shorter bills. Intensity and hue of the iridescent head and olive-green plumage colouration are determined by the degree of melanism, which increases southward and on all isolated islands but the Three Kings. Age and sex differences in plumage colouration are also caused by the different degrees of melanism. The degree of melanism may be reduced by the dryness of the environment, particularly in the period
before moult. Overlain on this cline are insular trends in morphometrics, colouration, moult, and breeding pattern. Bellbirds, particularly males, from isolated islands are larger than those on the mainland, whereas clutches are fewer and smaller, and breeding seasons and adult moult earlier. The sue increase occurs whether
other species of honeyeater are present or not and may result from high densities and the increased tendency of males and females to use different feeding niches. The relative body proportions of island populations vary and wing length does not increase as rapidly as body size. A new subspecies is described from the Poor Knights Is. It is characterised by a distinctly blue rather than violet iridescent head in males, an immature plumage phase, and other differences in sue, relative proportions, breeding, and time of moult. The nomenclature and taxonomic status of other island subspecies and of the extinct Northland bellbird A. dumerilii are reviewed. A. dumerilii and A. incoronata are regarded as synonyms of A.m. melanura.
The pair bonding, recognition, defence, and courtship displays of
the Red-footed Cormorant (Phalacrocorax gaimardi) are described for the first time. Similarity in displays reinforces van Tets’ contention that this species is a member of the Stictocarbo group. Its closest relatives seem to be the spotted shags of New Zealand waters and the European Shag. The Atlantic population of the Red-footed Cormorant is small and isolated, and it may differ from the much larger population along the Pacific coast by various behavioural and ecological features.
Between January 1965 and March 1967 4,926 observations were made on 20 species of petrel feeding in the Southern Ocean from the research ship USNS Eltanin. Most observations were made at night while the ship was stopped on oceanographic research stations. Observations were made possible by bright decklights, following birds with the powerful bridge lights, or under moonlight. Eleven feeding methods were distinguished. Most common were surface seizing [49.1%: used by 14 species), dipping (25.2%: 9 species), and surface plunging (c. 0.6%: 6 species). Seven species foraged entirely at night, and five fed by day only. Food recorded was chiefly crustaceans and squid. The submergence time and prey-handling time for some species are also given.
Over 27 months, 335 Brown Teal (Anas aucklandica chlorotis) were trapped and banded on Great Barrier Island. Four trapping methods were used to trap both solitary and flocking birds in all seasons. The efficiency of the trapping methods is compared, and the study areas and banding scheme are described. The computer program used to generate the colour band combinations is included as an appendix.