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.
The nesting activities and breeding success of Black Shags (Phalacrocorax carbo) near Lake Kohangatera, Wellington, were studied from 1993 to 1998. The colony was used during November-July by a mean of 67 birds per night, but in August-October numbers increased to a mean of 98 birds when fledglings were present. Courtship and nest- building began in March, and nesting continued until October-November when the last chicks fledged. Most clutches (85% of 185) were laid in April-May (early nests), the remainder being laid in June-September (late nests). The mean estimated laying date of early nests varied from 14 April in 1998 to 3 May in 1995, the overall mean (1993-98) being 24 April. During the day typically the male took two incubation stints, including the first, and the female one or two. The mean length of incubation stints by females was 3 h 46 min, over an hour longer than that of males. However, the mean time females and males were absent from the colony to forage, 2 h 39 mins and 2 h 21 mins respectively, did not differ significantly. Three types of changeovers seen during incubation are described, as are the activities of adults and chicks during nestling rearing. Fledglings took their first flights when 49-60 days old, but continued to be fed by their parents for 40 to 80 days afterwards, the oldest fledged young seen fed being about 140 days old. Of 185 breeding attempts during 1993-98, 83% were successful, the majority resulting in one or two fledglings per nest. Mean brood size at fledging varied with year, from 1.1 in 1997 to 1.7 in 1998. Overall, the mean brood size was 1.4 fledged young per nest, and 1.7 for successful attempts. Early clutches were more productive than late ones. We conclude that a pair of Black Shags would be unable to successfully rear two broods and complete their moult within a year, and that late nestings were replacement clutches.
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 (
Knowledge of the abundance of White-flippered Penguins and on the distribution of penguins without attached instruments at sea in general is scarce. Sightings of individual penguins in the neritic waters of southern Banks Peninsula were recorded between November 1993 and March 1997 to document their near-shore distribution and changes in seasonal abundance. White-flippered Penguins were not evenly distributed but appeared to concentrate in several bays. Abundance in Akaroa Harbour, the largest bay in the study area, peaked in April and November after recorded lows in March and September (probably due to moult and incubation), respectively.
Waders were counted monthly for six years at the three high tide roosts which are normally used by more than 50% of the waders in the Firth of Thames. The annual cycle of wader numbers is shown for all waders and selected species. The data are used to “correct” wader count data and demonstrate that such “correction” changes apparent population trends. Timing of future bi-annual wader censuses can be improved to maximise counts and/or to minimise variability.
Introduction to the transcript, W.H. Hartree, Jnr.
The number of Black-fronted Dotterels (Charadrius melanops) in the Ruamahanga River catchment of the Wairarapa, North Island, New Zealand, increased from c. 80 birds in 1972 to 300 – 350 birds in 1996. Another c. 100 birds breed on rivers that drain directly to the eastern coast of the Wairarapa. Their numbers and range are still increasing. Lake Wairarapa is an important wintering site for Black-fronted Dotterels, although their origin is uncertain.
Twenty four species and two subspecies of bird lice are recorded from New Zealand for the first time. Also, 52 new host-louse associations are listed for louse species already recorded from New Zealand. The genera Cuculiphilus Uchida, 1926, Franciscoloa Conci, 1942, Penenirmus Clay & Meinertzhagen, 1938 and Psittoecus Conci, 1942 are recorded from New Zealand for the first time. Since the publication of the previous list of chewing lice from New Zealand birds, four further lice have been published as new species, and another identified and reported in the literature. One species has been synonymised and its name is deleted from the fauna. Considering the above additions, deletion and other amendments, the total number of species and subspecies of bird lice recorded from the New Zealand region and the Antarctic Ross Dependency is now 301. A further 105 records still remain at generic level only, but all these do not necessarily represent different taxa.
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.
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.
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.