I recorded the calling behaviours of shining cuckoos (Chrysococcyx lucidus) from 1992 – 2015 on Kawau Island. The 3 most common calls, the upward crescendo “whistling call,” the downward slur “call-note,” and the “call-note” with “chatter” notes, were given from the arrival of adults in late August-early September until early January. After January only the call-note was heard. The upward whistling calls averaged 9.5 notes per calling bout (se = 0.18, n = 721). There was no significant difference in the number of whistling notes given with or without following notes. Single call-notes from lone cuckoos or groups of birds were restricted to specific sites on ridges. Calling was infrequently heard during evening twilight, and not heard during darkness. There was an increase in the number of cuckoo detections after 2009, and this corresponded with the appearance of communal behaviour and calling.
The valley of the South Branch of the Hurunui River, prior to 2001, held a dense population of the orange-fronted parakeet (Cyanoramphus malherbi). However, a rat plague in 2001 reduced this population by ~85%. In preparation for a restoration program of this species in the Hurunui valley, I analysed the distribution of sightings of orange-fronted parakeets, as well as the congeneric, yellow-crowned parakeet (C. auriceps) prior to the population collapse. My objective was to identify the areas and types of habitats used by each species. A vegetation survey showed significant differences between different parts of the valley floor study site, and this appeared to be reflected in the distribution of orange-fronted parakeets. Both species had significantly different distributions, and orange-fronted parakeets were recorded most frequently within forests growing on the river fan, an area characterised by mature red beech (Nothofagus fusca) and areas of dense regenerating mountain beech (N. solandri var. cliffortioides). While the valley has been subject to anthropogenic modification since the 1850’s, it still contains a relatively intact beech forest. My observations on the historic distribution of orange-fronted parakeets suggest this valley is still capable of supporting a large population of the species. However, the success of any re-introduction program is likely to depend upon continued preventative and reactive predator control, as well as a release programme that introduces enough individuals to prevent severe bottlenecks.
The breeding behaviour and development of New Zealand falcons (Falco novaeseelandiae) were recorded at 2 nests in Kaingaroa Forest during a 4-month period up to 2 March 2007. This covered the later part of incubation, and the entire nestling and early post-fledging periods. Incubation was shared between parents; the male primarily incubated the eggs, during which time the female hunted. The male only provided occasional prey for the female. Brooding by both parents was intensive for the first 6 days and then gradually declined until the chicks reached 14 days old at which point it ceased. Assisted feeding of the chicks was almost always undertaken by the female. The male’s primary role during the nestling period was prey delivery. During the early nestling period the female spent the majority of the time brooding chicks before shifting to hunting for the young.
We collated and reviewed 4179 records of the historic and contemporary distribution of the endangered specialist wetland bird, the Australasian bittern (matuku, Botaurus poiciloptilus), in New Zealand, to assess its current status and trends in its distribution across major habitat types. We mapped distribution in 5 time periods (pre-1900, 1900−1949, 1950−1969, 1970−1989, post-1990). We found that Australasian bittern are currently found throughout New Zealand with strongholds in Waikato, Northland and Auckland regions (46% of records) in the North Island, and Canterbury and West Coast (22%) in the South Island. They occur widely in freshwater and brackish riverine, estuarine, palustrine and lacustrine habitats. Australasian bittern were abundant (records of groups >100 birds) in Māori and early European times, but historical maps indicate their range appears to have been reduced by c. 50% over the last hundred years, with the most dramatic shrinkage in range occurring post-1970. Marked declines in occupancy began in Otago, Canterbury, Waikato, Wellington and Auckland regions between the 1900-1949 and 1950-1969 periods and reductions in range have been steady since. In comparison, declines in Northland, Southland, West Coast and Tasman/Nelson appear to be more recent and greatest between the 1970-1989 and post-1990 periods. The apparent shrinkage in range is supported by numerous observations in the literature. Australasian bittern distribution is now biased towards coastal areas and lowland wetlands of the North Island. Information indicates that range reductions were paralleled by marked declines in numbers: 34% of pre-1900 records were >1 bittern and 7.3% were >10, whereas post-1990, only 19% of records were >1 and 0.7% >10. The clearance and drainage of wetlands (c. 90% loss) and shooting were major causes of declines, but contemporary threats include continued habitat loss and degradation, accidental deaths from a range of causes, and predation by introduced mammals. Current trends in Australasian bittern populations suggest that they should be reclassified as Nationally Critical under the New Zealand threat classification system. Conservation management should focus on restoration of hydrology, water quality and aquatic food supplies, predator control, reedbed management and maintaining regional wetland networks.
Eight species of nationally declining river birds currently breed on the Ashley River, less than 1 km from the townships of Rangiora, Ashley, and Waikuku Beach. Threats to their breeding include human interference, mammalian predation, and vegetation encroachment in the riverbed. The numbers of at least 3 of these species appear to have declined from 1963 to 2000, in line with national trends. In 2000, a Rivercare Group commenced a public awareness campaign about the plight of the birds, trapping introduced predators, and clearing vegetation in parts of the riverbed. Annual surveys from 2000 to 2015 show a significant increase in numbers of banded dotterel (Charadrius bicinctus), wrybill (Anarhynchus frontalis), black-fronted tern (Chlidonias albostriatus), and pied stilt (Himantopus himantopus). Numbers of the other 4 species, including black-billed gull (Larus bulleri), the most threatened, have not changed significantly, in contrast to declining national trends. We suggest the Rivercare Group’s management actions have contributed to these successes, and support continuation of their actions.
Waterbirds were counted over ~ 12 ha of Western Springs Lakeside Park, Auckland, twice-monthly from November 2012 to October 2014. On average there were 742 water-birds per count (s.d. = 151.7, range = 511–1081), equating to a mean density of about 62 birds/ha within the study area. The 3 commonest species (mallard, Anas platyrhynchos, black-backed gull, Larus dominicanus and feral goose, Anser anser) made up 63% of all waterbirds counted. Mallard (and all waterbirds combined) were most abundant in summer and autumn. Black-backed gull, Eurasian coot (Fulica atra) and New Zealand scaup (Aythya novaeseelandiae) were seasonally uniform in numbers but red-billed gull (Larus novaehollandiae) were virtually absent from September to December. Spring was the peak season for numbers of black swan (Cygnus atratus), but the seasonal minimum for feral geese. Incidental historical counts trace temporal changes at Western Springs Lake, with a rapid increase of coots in the 1980s and of scaup in the 1990s. Royal spoonbill (Platalea regia) arrived more recently. The counts quantify for the first time the importance of the lake as a habitat for common water-birds on the Auckland isthmus.
The use of DNA barcodes (haplotypic variation in a 648 bp segment of the cytochrome c oxidase subunit I [COI] gene within the mitochondrial genome, starting from base 58 at the 5’ end of the gene) as part of a species description is an accepted part of modern taxonomy. The evidence COI provides is compelling since a sequence of DNA is biological data obtained from living material. Early in the use of COI, it became apparent that it might highlight potential cryptic species and inform the debate around their status. The little penguin (Eudyptula minor) has been the subject of such debate. DNA barcodes from 53 little penguins were assessed to determine the specific status of this species across its range. Analysis of these data indicates distinct Australian and New Zealand haplotypes that may be indicative of separation at the species level. The specific status for the 2 populations is also supported by behavioural evidence and geographic isolation.
The foraging ecology of Pitt Island shag (Stictocarbo featherstoni) was studied using GPS archival and Time Depth Recorder devices deployed on incubating birds. Pitt Island shags foraged exclusively during daylight, with a tendency for males to forage mainly during mid-morning and late afternoon, and females in the early morning and around mid-day. Mean foraging distance from colonies was 5.2 km (range 0.4-18.2 km), with males (mean 9.7 km) foraging significantly further than females (3.7 km). Both sexes showed high foraging site fidelity. The depth of most (83%) dives > 5 m deep were similar to the depth of the preceding dive (within 30%), indicating that birds are almost exclusively benthic feeding with the small fluctuations in dive depth likely reflecting changes in seafloor topography. Mean dive depth was 6.6 m, with maximum depth 24.4 m, although 90% of all dives were shallower than 13 m deep. Mean dive duration was 22 s, with a maximum of 69 s, although over 90% of dives were shorter than 40 s. There was a positive relationship between dive duration and dive depth, where deeper dives had longer duration. Mean rest period was 19 s with a weak positive relationship between rest period and duration of the preceding dive. Mean percentage time underwater during each foraging trip was 50.1%, indicating relatively high foraging efficiency. Favoured foraging locations in shallow inshore waters is likely to be a response by birds selectively foraging in sheltered waters protected from oceanic swells. This may be a factor influencing population declines as it intensifies risk to birds as potential threats may be more concentrated in these areas.
Hutton’s shearwater (Puffinus huttoni) currently breeds only in 2 colonies in the Seaward Kaikoura mountains, South Island, New Zealand. Conservation measures now include re-locating young to establish a new low altitude colony. To assess the genetic similarity of birds breeding in the 2 colonies as a basis for decisions on sourcing recruits to the present and potentially other new colonies, we genotyped 9 microsatellite loci, with 3-13 alleles, in 30 birds from the Kowhai River catchment colony and 29 from Shearwater Stream. There was no significant population genetic differentiation between the 2 sampling locations. Our results suggest that there would be little genetic risk to mixing birds from both relict colonies in newly established colonies. Future analyses of the former distributions of Hutton’s shearwater, the fluttering shearwater (P. gavia), and the extinct Scarlett’s shearwater (P. spelaeus) will require an analysis of the levels of genetic similarity between birds from the relict colonies and those of former, widely separated colonies.