The total population of New Zealand king shag (Leucocarbo carunculatus) was counted for the first time during the 1992 breeding season. At 524 birds, numbers were almost twice as high as estimated previously. The daily rhythm, foraging range and feeding location of king shags from the Duffers Reef colony in the Marlborough Sounds were studied in 1991 and 1992. The mean (± s.d.) foraging range was 8.2 ± 4.1 km (maximum 24 km) from the colony. Most (74%) fed in 31% of the study area, 20-40 metres below the surface on a mainly flat bottom, within the confines of the outer Marlborough Sounds. During the six months courtship/breeding period, daily rhythm of the colony was different from the rest of morning and afternoon. It is assumed that females left to feed in the morning and males in the afternoon to feed and collect nesting material. No double peak was seen during the non breeding period.
The endemic New Zealand shore plover (Thinornis novaeseelandiae) is confined to a small population on Rangatira (South East Island) in the Chatham Islands. There are about 43 breeding pairs and 130 adults. The population is sedentary. Shore plover form monogamous breeding pairs in separate defended territories. Clutch size, parental behaviour, courtship, and defence displays are similar to those of other plovers. Shore plover have several unusual breeding characteristics which may be responses to the relatively constant environment and limited area of habitat on Rangatira, low prey abundance, differences in habitat quality, no mammalian predators, and the presence of certain avian predators. Shore plover are unique among plovers in nesting under cover, which protects their nests from avian predators and temperature extremes, but which would make nests very vulnerable to predation by mammals. Environmental conditions on Rangatira may also be a reason for the high hatching rate, low chick survival, and differing breeding success within the population.
Since the first burrows of Chatham Island taiko Pterodroma magentae were found in 1987/88, trapping around the burrows has killed 204 feral cats Felis cattus, 3053 possums Trichosurus vulpecula, 1572 weka Gallirallus australis and 589 rats Rattus spp. in 109,892 trap-nights to March 1993. No Taiko are known to have been killed by predators. Productivity was static at one fledgling per year until 1992/93, when two fledglings were reared. Unobtrusive studies of breeding biology indicated that mating occurred about 1 October, laying about 26 November, hatching about 20 January and fledglings departed about 4 May. The pre-laying exodus of females lasted up to 50 + days and chick-rearing took about 105 days.
The Incredible Kiwi
Kiwis. A Monograph of the family Apterygidae
Kiwi – A Secret Life
Handbook of Australian, New Zealand & Antarctic Birds. Vol I, Ratites to Ducks
The brushtail possum (Trichosurus vulpecula) is an opportunistic herbivore feeding mainly on leaves supplemented by a variety of other plant materials. Possums are known to eat more than 100 native plant species and a wide range of introduced plants. Diet varies markedly between regions but within any particular region is concentrated on a few plant species (Green 1984). In addition to plant material, possums will eat invertebrates (Gilmore 1967, Clout 1977, Warburton 1978, Morgan 1981, Cowan & Moeed 1987) and small vertebrates, such as birds (Perham 1924, Morgan 1981) and mice (Cowan 1990). Captive possums readily accept meat (Cowan 1990). This article describes remains left by possums that have fed on birds and their eggs. Feeding trials were carried out with captive possums to see whether they would eat dead birds and eggs and to see what sign remained after feeding. In addition, we have brought together various accounts of possums preying or scavenging on birds and other animals.
Historical records of South Island breeding of NZ dotterel (Charadrius obscurus) are discussed. The latest discovered South Island breeding record was 1881. No record of South Island coastal breeding was found. Numbers of birds wintering on the Southland coast declined substantially and rapidly from 1972 to 1992. The cause of decline is believed to be a decline in the Stewart Island breeding population. Colour-banded adults had allegiance to a specific wintering ground. Food items of birds at Stewart Island included 10-20 mm juvenile flounders.
The chocolate albatross of Latham (which was the foundation of Diomedea spadicea of Gmelin, 1789) was based for all relevant taxonomic purposes on the painting by Sydney Parkinson of a wandering albatross taken in 1768 in the South Atlantic Ocean off the Rio de la Plata, Daniel Solander’s manuscript description of the specimen indicates it was probably an example of the population breeding at the Tristan da Cunha group and Gough island, in which case dabbenena of Mathews, 1929 as the name of the subspecies would be pre-dated by 140 years by spadicea of Gmelin, 1789. Continuing confusion over the identity of the population to which the wandering albatross described by Linnaeus belonged has prompted a full examination of the sources on which he based his Diomedea exulans. As a result of this examination it is concluded that exulans as the name of the nominate subspecies of the wandering albatross is properly applicable to the larger southern populations which breed at South Georgia, Marion and Prince Edward, Crozet, Kerguelen and Macquarie Islands.