A colour-banded population of Riflemen at Kowhai Bush, Kaikoura, New Zealand was studied to determine the contribution of males to the care of young. Parental care and territorial behaviour were qualitatively the same throughout the breeding period. Males fed the females during courtship and in this way contributed the food required to produce the first clutch of eggs. Males made 66% of nest-building visits (early nests), spent 50% more time incubating than their mate by day (both clutches), leaving the females the thermo-insular advantage of incubating at night, always fed young significantly more often than their mate and contributed 55-77% of all food items fed to broods without helpers (the great majority of nests), and shared territorial defence equally with their mate. However, nest-building and territorial defence occupied less than 1% of parents’ time early in the breeding season. One widower was unable to fledge young alone. Early season sex ratios for the years studied were (M:F) 22:15, 50:35, 39:37 and 20:21 with extra males sometimes becoming helpers. The male’s high parental effort was not reflected in significantly lower survival to the next breeding season. Possible reasons for the large contribution by the male Rifleman to the breeding effort are discussed.
Between 1940 and December 1993, 66 species of landbirds (including shore and freshwater birds) were recorded at the Chatham Islands. Of these, 38 were native and introduced breeding species, 4 were regular summer visitors and 24 were occasional visitors or stragglers. Published and unpublished records of these species on the Chatham Islands are summarised.
The diet of Red-crowned Parakeets (Cyanoramphus novaezelandiae chathamensis) and hybrids (C. n. chathamensis x C. auriceps forbesi) was determined from crop contents and field observations. Crops were dissected from 220 Red-crowned and hybrid birds collected over four years on deforested Mangere Island in the Chatham group. Volume and prevalence of foods taken in winter, spring and summer were measured. No effect of sex or age was found on frequency of occurrence of food items, and low variation in diet attributable to species hybrid status indicated that feeding strategies of the parent species had converged. Diet of all forms varied seasonally. The main winter food was grass seeds, with a small proportion of leaves. The spring diet was the most varied, consisting mostly of leaves, with seeds, flowers and invertebrates. Seeds were eaten in late summer, mostly from Geranium traversii. Field observations in winter emphasised the importance of leaf feeding. Some plant species seen to be eaten in summer were not found in crops. Habitat selection and perch height distribution was associated with breeding requirements as well as feeding.
Brown skuas (Catharacta skua lonnbergi) on rangatira (south east) and mangere islands in the chatham islands group were studied over a period of 14 years (1978/79 to 1992/93 breeding seasons) to determine factors promoting cooperative breeding in this population. The size and composition of the breeding population and overall breeding success were remarkably stable. No significant differences in breeding success, density of territories or periods of individual occupation in different places on these islands were demonstrated that would demarcate optimal and marginal breeding habitat. Neither could it be demonstrated that the islands were saturated by breeding birds as required for a habitat-forced origin of cooperative breeding.
The migration pattern of Cattle Egrets in 1990 and 1991 and its relation to meteorology are presented to extend initial results covering 1987-1989 (Maddock & Bridgman 1992). Cattle Egrets migrated to Victoria and Tasmania in waves during March and April in northerly air flow (western side of a high pressure system) in a series of stages, with periods of rest in between. Major staging points seemed to be Windsor (NSW), Nowra (NSW), and Baimsdale (Vic). Return migrations (October and November) appeared faster, with fewer and shorter rest stops, and were in southerly airflow. Staging points were Werribee (Vic), Nowra (NSW), and Wyong (NSW). Migrations to and from New Zealand were much more limited than in previous years due to adverse weather conditions, especially winds.
Records of Chatham Petrel (Pterodroma axillaris) up to 1989 are reviewed. A research programme that started in the breeding season of 1989/1990 to locate more individuals and more active burrows is described. Several methods of locating birds were employed and status of all burrows, and breeding success and measurements of all birds were recorded. The population at the end of the 1991/1992 breeding season is estimated. Conservation issues presented by the species are discussed.
The Chatham Island Taiko (Magenta Petrel) Pterodroma magentae is endangered, with a population of about 50 birds. Conventional searches from 1970 to 1986 failed to find its breeding sites. Trials of radio transmitter packages attached to Grey-faced Petrels P. macroptera gouldi and to six Taiko in 1982-1986 were satisfactory. In a major effort to find burrows, Taiko were caught and radio-tracked over three months in late 1987. Twelve Taiko were caught at night with the aid of lights. Ten birds were each fitted with a transmitter; all flew out to sea after release. Birds were tracked on 16 later occasions. Two tracked birds landed 4-6 km inland in dense bush. On subsequent searches at the bearings at which the signals became stationary, five burrows were found, in two areas, 4 km apart. During a similar operation in 1988 no Taiko were caught. Despite extensive searches, these were still the only breeding areas known in late 1993.
In 1992, participants of the Beach Patrol Scheme patrolled 4114 km of the New Zealand coastline. 5994 dead seabirds of 53 species plus 143 individuals of 30 other bird species were recovered. The number of seabirds found in 1992 was only 59% of the annual average of 10 187 between 1971 and 1992, and was the seventh consecutive year that below average numbers of dead seabirds have been found. The Common Noddy (Anous stolidus pileatus) was recorded for the first time since the start of the Scheme, providing the second record of this species in New Zealand. Thirteen Little Shags (Phalacrocorax melanoleucos) were found, more than the average of 5-10 per year during 1971-1992. 14 833 specimens of three species of gulls were recovered between 1943 and 1992. The majority of recoveries (10 190 bids) was that of the Southern Black-backed (Larus d. dominicanus), which was found mostly near coastal cities when birds dispersed from the colonies after the breeding season. 4195 Red-billed Gulls (L. novaehollandiae scopulinus) were found during 1943-1992, mainly along the eastern coasts of New Zealand. Only 448 Black-billed Gulls (L. bulleri) were found during the same period, mainly on eastern South Island beaches.