Late-August censuses gave minimum New Zealand totals of 266 Cattle Egrets (Bubulcus ibis) in 1978, 624 in 1979, and 771 in 1980. This rising trend ceased in 1981 and 1982. The three years’ records are given for each region, and the late-August distribution is mapped. Arrival of birds was conspicuous in late April and early May and probably continued into June. A bird banded as a nestling in northern New South Wales was recovered, and a second banded bird was seen. Arrival was widespread,
mainly in the west, and by June most birds had moved to traditional farms. The main departure period seemed to be midOctober to mid-November, but many birds remained to December. A few over summered each year and passed through breeding
plumage. In New Zealand, the birds are very shy of humans, even though they associate with various gregarious farm animals, mainly cattle and sheep. In the New Zealand winter, the main observed food of the egrets is earthworms. Differences of plumage from the nominate race and the development of breeding plumage are
discussed.
Thirty-one records from Kowhai Bush and the Nest Record Scheme show that Shining cuckoos (Chrysococcyx lucidus) laid from mid-October to early January. At Kowhai Bush, a cuckoo was seen to “freeze” while it apparently watched a pair of Grey warblers (its host), and warblers were distressed when a stuffed cuckoo was put near their nest. Dissection of a female cuckoo disclosed an egg-shell (probably a warbler’s) in its gizzard. The newly hatched Shining cuckoo bears natal feathers (trichoptiles) and is thus unusual among Cuculinae. The physical and behavioural development of nestlings is described, and weights and tarsal lengths are given. Fledgling cuckoos were fed by their foster parents for up to 28 days.
A study of the Sooty Shearwater (Puffinus griseus) was made at the Snares Islands during four summers. The work is based partly on the activities of 31-45 marked pairs in burrows and partly on more general observations. These Iarge, powerful shearwaters (weight 819 g) return in late September and, after a ‘scratching-out’ period of about a month, part of the population leaves on a prelaying exodus which lasts about two weeks. Laying reaches a peak from 20 to 24 November and incubation takes 53 days, most eggs hatching from 11 to 16 January. No precise nestling
periods were obtained, but adults depart on migration from the end of March and most leave by the third week of April. Most chicks leave during the last weeks of April and the first week of May. Surface-laid eggs are plentiful. They tend to be smalIer and narrower than burrow-laid ones and, on average, are laid three days later than those underground. During incubation the male takes the first stint on the egg after the female’s brief initial one. Thereafter the stints are of similar length, averaging about
9.4 days for both sexes. Samples of chick weights for their first 40 days are given as well as weights of 500 chicks at the time of banding just before their first flights. Flooding of burrows is the chief overt cause of chick mortality. Differences in timing
of breeding at Whero Island and The Snares are discussed. In general, the timing seems to be similar throughout the birds’ range from Australasia to the Falklands and Tierra del Fuego,
Re-examination of the type material of Anomalopteryx oweni (Haast) indicates that this taxon should be synonymised with A. didiformis (Owen).
Fewer than 50 adult Spotless Crakes (Porzana tabuensis) plus 24 chicks and
four juveniles were found on Aorangi in February and March 1980. They were confined to the valley and preferred a low mixed forest which is being replaced by a less favoured habitat. Habitat preference is discussed and related to changes in numbers
in the past. Clutch size is lower than on the mainland and chick production probably lower. The breeding cycle is long. Some observations on the adult-chick relationship are presented.
By means of data in the literature and a large sample of sexed birds from Signy Island, South Orkney Islands, Snow Petrels (Pagodroma nivea) are shown to be sexually dimorphic in size and especially in body weight and bill length. By these characters alone, over 80% of Signy birds can be correctly sexed. It is suggested that the true status of the so-called large and small forms of the species can best be resolved by comparing birds of known sex and status. The sexual dimorphism in weight in Snow Petrels is amongst the greatest in the Procellariiformes and might relate to the extensive use of vocalisations in individual and sex recognition.
In November 1980, two Leach’s Storm Petrels of the typical subspecies (Oceanodroma
leucorhoa leucorhoa) were discovered on Rabbit Island, Chatham Islands (44″14′ S, 176″16′ W), engaged in prebreeding activity. They were captured, examined, photographed, banded and released. The flight calling of one was recorded on tape. Their nocturnal activitv continued until observations ceased. A subsequent check indicated that no chick was reared. Possibly they were of the same sex, and possibly there were only two. This is the first record of prospecting for nest sites in the Southern Hemisphere by this strictly Northern Hemisphere breeding species.