Publications Archive

Osteological characters distinguishing the South Georgian Diving Petrel (Pelecanoides georgicus) from the Common Diving Petrel (P. urinatrix) are described. P. georgicus is shown to be the main diving petrel in Holocene fossil deposits at Mason Bay, Stewart Island, New Zealand, where it is represented by thousands of bones. P georgicus is also recorded from dune deposits on Chatham Island. The Codfish Island population is thus a remnant of a formerly large Pacific population that bred on Macquarie Island, Auckland Islands, Stewart Island and Chatham Island, and is therefore of high conservation priority.

The North Island Weka (Gallirallus australis greyi) population at Parekura Bay was monitored in 1991-95, during a long dry El Nino event. Adult Weka had declined from ~400, in February 1987 (Beauchamp 1988), to 47-63 Weka in Parekura Bay and Whangamumu areas in June 1991. By March 1995 there were only three Weka left there. Enhanced production of young Weka was insufficient to prevent decline. Known mortality factors were road kills, Timms traps and dogs and stoats. Throughout the study the population lacked females. A “crowing call” by males was identified as associated with mate loss and mate finding.

We examined digestive tract contents and stable nitrogen isotope ratios (15N) in breast muscles of Buller’s Shearwaters (Puffinus bulleri) salvaged from squid and large- mesh driftnets in the central North Pacific Ocean. The epipelagic Pacific Saury (Cololabis saira) was the predominant prey, making up 71% of prey mass in digestive tracts. The remainder of the diet included small numbers of crustaceans, small fishes, and squids. The high degree of specialization in the diet seems to indicate that in the North Pacific, Buller’s Shearwaters usually feed at or near the water surface and rarely pursue food under water. Although these birds have been observed feeding on scraps from fishing vessels, our data suggest that offal comprises less than 10 percent of the diet. Stable nitrogen isotope values provided quantified information on the timing of arrival of migrants into the North Pacific.

A breeding male Chatham Island Taiko (Pterodroma magentae) was found recently dead of injuries by its burrow on 14 November 1996. Intraspecific fighting followed by sepsis of wounds seems the likely cause of death. All parts were preserved. Food items of Taiko include four squid species and one fish species. Its intestinal structure suggests a close relationship with the P. mollis group and P. macroptera. Measurements of bones indicate that most subfossil bones previously referred to this species were correctly identified.

Twenty species of birds are recorded from Kapingamarangi Atoll, southern Micronesia, 14 sea- and shorebirds and six land birds. Eleven are documented or probable breeders or former breeders. The Micronesian Starling (Aplonis opaca) is the only native, resident land bird, and it is common and widespread, averaging 5.7 birds ha-1 atoll-wide among the 31 islands. A kingfisher is reported from Kapingamarangi for the first time, and a recently collected specimen of Shining Cuckoo (Chysococcyx lucidus) is the first record for Micronesia and first report of the nominate (New Zealand) subspecies north of the Bismark Archipelago.

The diet of New Zealand King Shags (Leucocarbo carunculatus) in Pelorus Sound, South Island, New Zealand, was deduced from diagnostic prey remains in 22 complete regurgitated pellets collected as two samples taken six months apart. Pellets represented a total of ahour 683 prey items with an estimated wet mass of 14.9 kg. Witch (Arnoglossus scapha), a lefteyed flatfish (Bothidae), dominated the diet and accounted for about 90% of prey items and 95% of wet mass in both samples, but there was a change in the average size taken. The average total wet weight per pellet matched the theoretical estimate for daily energy expenditure for the shags. Prey species of interest to commercial or recreational fishers accounted for only 1.3% of the diet. These results are applicable only to the 25% of the species total population that forages in Pelorus Sound. An investigation of the diet elsewhere in Marlborough Sounds is recommended in order to determine if the small population size and restricted distribution of King Shags are related to the availability of food.

The archaeological and fossil avifauna of Niue Island in the southwest Pacific is described from ten sites. Fourteen species of birds, including an extinct species each of Gallirallus and Nycticorax, and an extirpated megapode (Megapodius pritchardii) were found. This increases the number of taxa known for the Niue fauna to 15 resident species, but faunas from surrounding islands indicate this is almost certainly an under-estimate of original diversity.