Banded dotterels (Charadrius bicinctus bicinctus) exhibit a variety of seasonal movement patterns ranging from sedentary behaviour, through migration within New Zealand, to trans-Tasman migration. From 1985 to 1990 the Ornithological Society of New Zealand (OSNZ) studied the regional patterns of movement of banded dotterels which had been colour-banded on the breeding grounds. Sight-recoveries indicated that most birds in inland regions of the southern half of the South Island migrated to Australia, but coastal breeding birds in the South Island were mostly sedentary. Inland birds north of Canterbury mostly moved within New Zealand, particularly to harbours in the North Island but with regionally specific patterns – Westland birds mainly to Farewell Spit, Marlborough birds to the northern North Island and Farewell Spit, southern North Island birds either locally or to the Auckland region, and most Hawkes Bay and Volcanic Plateau birds to Bay of Plenty and Auckland. Breeding habitat modified this pattern; coastal birds were mainly sedentary, whereas birds on nearby inland riverbeds were migratory. Migration patterns are discussed in terms of advantages and disadvantages of different wintering options.
I tested the ability of captive black stilt chicks (Himantopus novaezelandiae) to capture and consume common aquatic invertebrates. Waterboatmen (Sigara sp.), segmented worms (Oligochaeta), and larvae of a damselfly (Xanthocnemis zealandica), midge (Chironomus zealandicus), mayfly (Deleatidium spp.), and caddisfly (Aoteapsyche colonica) were captured and consumed quickly and easily by chicks of all ages (2 – 30 days). They were also consumed in the greatest numbers. In contrast, two aquatic snails (Physa acuta and Lymnaea tomentosa) and larvae of two cased caddisflies (Triplectides sp. and Hudsonema amabilis) were captured and consumed with difficulty and in low numbers by young chicks (< 7 days). Young chicks appeared to take longer than older chicks to capture prey, to spend more time manipulating prey in their bills before swallowing, and to drop prey frequently. In contrast, 21 – 30 day old chicks appeared to capture, manipulate and swallow most types of prey efficiently and quickly. These results augment biomass as a measure of the value of aquatic invertebrate food supplies in wetlands.
Population trends in the western weka (Gallirallus australis australis) in Golden Bay and the Marlborough Sounds were examined by field surveys and reference to the literature. Weka declined on the southern margin of Kenepuru Sound in 1995-96, but they were still at 0.10 and 0.06 ha-1 at Big Bay, Endeavour Inlet, and Long Bay near St. Omer, respectively. Weka numbers have declined in lowland Golden Bay to less than 0.01 ha-1 since 1986. The reasons for this declines is unknown, but it appears that high densities of mustelids peaks and climatic extremes are times when weka populations need close monitoring.
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 (Chrysococcyx 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.
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.