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.
Wrybill (Anarhynchus frontalis) and banded dotterel (Charadrius bicinctus) are territorial birds which breed on braided riverbeds in Canterbury, New Zealand. Home ranges of wrybill pairs were bigger than those of banded dotterel pairs on the Rakaia and Ashley Rivers. For wrybill there were no significant differences in home range size between years and rivers, but home ranges of banded dotterel pairs were larger on the Rakaia R. than on the Ashley R. Wrybill home range size on the Rakaia R. was related to the presence of preferred minor channel feeding habitats; small home ranges contained mostly minor channels and large home ranges contained mostly major channels. The larger home ranges for banded dotterel on the Rakaia R. is thought to be related to greater habitat instability compared to the Ashley R. If large scale diversion of water occurs from these rivers then flows need to be managed so that the characteristics of the natural flow regime are maintained.
Natal philopatry of 859 southern Buller’s mollymawks (Diomedea bulleri bulleri) banded as chicks on North East Island, The Snares (48°02’S, 166°36’E), during August 1972 was investigated during 1977 to 1998. Eighty-six birds were recaptured as breeders; 57 of these were recorded within 100 m of their natal nest area and 29 dispersed over distances ranging from 100 m to 2430 m. The gender of 32 birds was determined by measurements of minimum bill depth and tarsus width, or by their behaviour. Of 17 males, 15 were found breeding within 100 m of their natal site and the remaining two birds dispersed 100 – 200 m. Of the 15 females, five were breeding within 100 m of their natal site and the remainder had dispersed 100 – 1640 m.
Six nest sites of New Zealand falcon (Falco novaeseelandiae) breeding in a mixed podocarp hardwood forest are described. All nest scrapes were located in Collospermum hastatum epiphytes on emergent. Nest height was about twice the height of the surrounding canopy. All but one nest trees were alive and appeared to be in good health. The large diameter (mean at breast height: 105 cm) and the height of nest trees (mean 36 m) indicated that falcons selected older trees in the forest. Nests tended to be located mid-slope or towards a gully and of northerly aspect. Management of New Zealand falcon habitats should involve the maintenance of adequate emergent trees in forests, from which falcons can select appropriate nest sites.
The body composition of ten adult and five juvenile knots (Calidris canutus rogersi) in the migratory period from Northland, New Zealand, was studied. Basic physical measurements of all individuals are provided. Adults were heavier than juveniles, but showed a large variation in mass – some were at estimated departure mass while others apparently were only in the early stages of mass increase, allowing an investigation of changes during the “fattening” procedure. Changes in fat-free dry tissue (protein) of organs were complicated, with pectoralis and heart muscles increasing with total fat mass, while intestine and stomach mass decreased. This resulted in total fat-free dry tissue firstly increasing with fat mass, then levelling off or decreasing. This reallocation of protein is interpreted as being a method of freeing up muscle protein for redeposition in other organs during premigratory fuelling. Most fat was deposited subcutaneously, apparently in a linear fashion. In contrast, abdominal fat showed proportionately higher masses as total fat increased, while fat around other organs showed the reverse pattern. Adults were significantly larger than juveniles in ten organ comparisons, but only four of these were clearly related to migration. Organ sizes in C. c. rogersi were much smaller than in the European-wintering C. c. islandica, and slightly smaller than African-wintering C. c. canutus. Salt gland mass of C. c. rogersi in this sample from New Zealand was much larger than that known from European birds, which may reflect migratory preparation. Lean mass was estimated at around 109 g.
The Chatham Island pigeon or parea (Hemiphaga novaeseelandiae chathamensis), is the endangered subspecies, endemic to the Chatham Islands, of the New Zealand pigeon or kereru (H. n. novaeseelandiae). During the early period of European and Maori settlement, 1820s to 1870s, parea were common on Chatham, Pitt and Mangere Islands, but by 1990 the population possibly comprised fewer than 50 birds, mostly in forest habitats of the southern part of Chatham Island. Between 1989 and 1994, the numbers of feral cats and brushtail possums (Trichosurus vulpecula) were reduced in areas occupied by parea in the Awatotara and Tuku Valleys of south-western Chatham Island The adult parea population of these valleys increased three-fold from 27 in 1990 to 81 in 1994. The long-term future of the parea is dependent on the exclusion of cattle, pigs and sheep from forest reserves. Keeping cat and possum numbers at low levels in parea habitat on Chatham Island, and the establishment of a population on Pitt Island once cats have been removed from one or more of its reserves.
Wetland birds on 11 rivers of the upper Waitaki basin, South Island, New Zealand were surveyed annually between 1991 – 1994. Diversity, minimum abundance and density of birds were compared. In total 26 species of wetland birds were recorded. Minimum estimated river bird numbers were: 3566 black-backed gulls (Larus dominicanus), 3302 black-fronted terns (Sterna albostriata), 3260 banded dotterels (Charadrius bicinctus), 793 black-billed gulls (Larus bulleri), 789 wrybills (Anarhynchus frontalis), 788 South Island pied oystercatchers (Haematopus ostralegus), 421 pied stilts (Himantopus himantopus), 85 black stilts (Himantopus novaezelandiae), 51 Caspian terns (Hydroprogne caspia), and 3680 waterfowl and cormorants. Densities of birds ranged from 0.17 birds ha-1 on the Pukaki River to 0.95 birds ha-1 on the Lower Ohau River. The Cass, Lower Ohau, Godley, Tekapo and Ahuriri Rivers had higher densities of one or more species than the Upper Ohau and/or Pukaki Rivers. Densities of black-fronted terns, black stilts, pied stilts and Caspian terns were negatively correlated with altitude, and in general birds preferred river sections with low or moderate flows, and low or moderate vegetation cover. Eight of the 11 rivers surveyed had more than 1% of estimated total populations of one or more of three globally vulnerable or endangered species, and in combination rivers of the Upper Waitaki Basin support almost all known black stilts, 15% of all wrybills and 32% of all black-fronted terns. We suggest that the Upper Waitaki Basin may now provide half of all remaining suitable braided river bird habitat in New Zealand.