The eastern shore of Lake Wairarapa is a nationally important site for waders. The monthly distributions of eleven species of wader and of white-faced herons (Ardea novaehollandiae) are presented from monthly counts between November 1983 and October 1994. Numbers of spur-winged plovers (Vanellus miles) increased dramatically during this period. Water levels in this shallow freshwater lake vary with regional rainfall, the management of floodgates at the outlet of the lake, and wind direction and strength. Numbers of pied stilt (Himantopus himantopus), banded dotterel (Charadrius bicinctus) and black-fronted dotterel (C. melanops), for which the lake is an important wintering site, declined once the water level rose over about 10.3 m above an imaginary reference point (datum), and also declined below about 9.95 m above datum. Our findings confirm the importance of managing lake levels and we discuss how these data were used in setting operating levels for a water right application to operate the floodgates at the outlet of the lake.
During 1996, participants in the Beach Patrol Scheme patrolled 3071 km of the New Zealand coastline. There were 4649 dead seabirds of 58 species recovered by patrollers. In addition, beach patrollers found 165 birds of 32 non-seabird species. Unusual finds included one Chatham Island mollymawk (Diomedea cauta eremita), one New Caledonian petrel (Pterodroma leucoptera caledonica), two channel-billed cuckoos (Scythrops novaehollandiae) and two spine-tailed swifts (Hirundapus caudacutus). There was a moderate-sized wreck of sooty shearwaters (Puffinus griseus) on North Island west coast beaches in November. The highest annual totals of Pitt Island shag (Stictocarbo featherstoni) and Chatham Island shag (Leucocarbo onslowi) were recorded in 1996. The mean annual recovery rates of Buller’s mollymawks (Diomedea bulleri) and black-billed gull (Larus bulleri) were the highest recorded since the start of the Beach Patrol Scheme. Red-billed gulls (Larus novaehollandiae scopulinus) had their lowest annual recovery rate in 1996. Causes of seabird mortality are discussed in the paper.
Snares Island snipe (Coenocorypha aucklandica huegeli) were studied on the Snares Islands during parts of six breeding seasons between 1982 and 1987. Laying was between 4 November and 19 February; the breeding season (including chick-rearing) spanned the months November to May. Nests were well concealed among dense vegetation with solid overhead cover. Most birds were monogamous, with shared incubation of the two-egg clutch. Males incubated for 51% of the time, mainly at night and during late afternoon; females incubated 49% of the time, mainly during the morning and early afternoon. The eggs hatched synchronously and the chicks stayed in the nest for less than 13 h. The male cared for the first chick to leave the nest. Growth of chicks is described using Gompertz equations. Full juvenile plumage took c. 54 days to attain, and adult size in all growth parameters was attained soon after independence (c. 65 days). Chatham Island snipe (C. pusilla) were studied on Rangatira Island during the 1983-84 breeding season. Laying was estimated to extend from late September to the end of December. Most nests found (86%) were under Carex sedges. Incubation of the two-egg clutch was shared; incubation patterns were not determined. The eggs were 19% smaller in relation to predicted egg-weight than those of Snares Island snipe. The eggs hatched synchronously and the chicks stayed in the nest for less than 11.5 h. The male cared for the first chick to leave the nest. Full juvenile plumage took c. 47 days to attain. The bill grew much more rapidly than for Snares Island snipe and chicks became independent much earlier (c. 41 days old).
We observed that South Polar skuas (Catharacta maccormicki) breeding near the Adelie penguin (Pygoscelis adeliae) western colony at Cape Crozier, Ross Island, Antarctica were able to forage throughout the colony, the majority of which was not defended by territorial skuas as in other Ross Island colonies. All local skuas were able to find enough food on the colony throughout January to support breeding and none were seen to forage at sea. Skuas foraged as individuals to obtain penguin eggs and chicks but kleptoparasitism usually occurred so that several skuas fed in turn on a single carcass. At the end of each feeding event a general melee occurred in which up to 30 skuas fought over the chick remains. The implications for skua breeding of this foraging regime, in which any skuas in the local area can obtain penguin food, are considered. We suggest that the high levels of food availability contributed to the unusually high success for this region of these skuas in raising both chicks. Desertion of chicks while foraging, however, leads to some mortality among older chicks later in the season through predation. It is recommended that further research on skuas at super-large penguin colonies be undertaken.
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.
Caspian terns (Sterna caspia) from an isolated colony in southern New Zealand were studied for 30 years. Aims of the study were to identify the birds’ wintering grounds and to discover the whereabouts of birds during immaturity, by tracing movements of known-aged birds. Adults moved to several wintering grounds up to 1150 km to the northeast. Some birds were locally nomadic in winter, but little distance nomadism was identified in adults. In some families, one parent left the colony up to three weeks before the rest of the family. Juveniles left their natal colony when aged 7–9 weeks, and each was accompanied by one parent until aged 8–9 months. Typically, parents took turns at accompanying a juvenile, in stints of ca. 1-3 days, but two siblings wintered 360 km apart, each accompanied by a parent. Birds on outward passage moved in stages in flocks of 2–4 birds. Families lingered at staging areas for 2-26 days. A 49–54 day old juvenile moved 195 km in five days. Mortality was high in juveniles which moved further than ca. 900 km. Seventy seven percent of juveniles remained sedentary at their wintering ground to age 9 months, and 30% stayed on at the same location through their second winter. Immature birds remained sedentary, were locally nomadic or wandered far inland. Some returned to the colony and stayed briefly, but those which had wandered tended to remain at one site for weeks or months before moving on. Juveniles begged only from their parents. Flight skills and some feeding behaviour of known-aged juveniles are described, as are some behaviours at staging areas.
Aerial surveys for flying seabirds were directed up to 18.3 km offshore from Banks Peninsula during February and July-August 1996. The abundance of Hutton’s/fluttering shearwaters (Puffinus huttoni/P. gavia) increased offshore, consistent with possible offshore increases in pelagic versus benthic productivity The decrease in abundance offshore of spotted/pied shags (Stictocarbo punctatus/Phalacrocorax varius), black-backed gulls (Larus dominicanus), white-fronted terns (Sterna striata), and red-billed/ black-billed gulls (L. novaehollandiae/L. bulleri) probably reflects their commuting to and from breeding and roosting sites. Hutton’s/fluttering shearwaters and white-fronted terns were most common around the area east of Banks Peninsula. The distribution of other species around Banks Peninsula probably reflects breeding site distribution (spotted shags), and feeding opportunities on land (black-backed gulls). Convergent fronts were distributed around Banks Peninsula, and decreased in number offshore. Internal waves were most common toward the eastern end of Banks Peninsula, and were evenly distributed offshore. While the onshore-offshore distribution of the non- procellariiform species matched that of convergent fronts, seabirds and individual convergent fronts did not significantly co-occur.