The distribution, status and trends of grey-faced petrel (Pterodroma macroptera gouldi) populations are summarised from historical records from as early as the 1800’s, but predominantly over a 40 year period from the 1970’s and 1980’s to the present day. We tallied the most recent of 104 island population estimates to give a total range of 72,398-286,268 burrows over a minimum area of 37,967 ha. On predator-free islands (n = 9) during winter, the mean burrow occupancy rate was 60% (± 18 % SD). Fewer than 1000 burrows were detected from 20 mainland sites over an unspecified area. Implications for the conservation of this species are discussed.
Bird counts were carried out in Zealandia sanctuary, Wellington, New Zealand, along a 6.3 km slow-walk transect, every 3 weeks for 4 years (2011-2015). The mean ± se number of species detected per count was 30.0 ± 0.4 (range 22-37) and the mean ± se total of individuals detected per count was 572.7 ± 12.8 birds (range 361-809). Of 43 species detected, 15 occurred on every count, 8 on most, 13 less frequently and 7 only occasionally. Forest birds were mostly first detected by sound, but water or wetland birds mostly by sight. For 35 species with sufficient data to model, significant seasonal changes occurred in 9 species (26%) and significant annual changes in 4 species (11%), with the total of birds counted peaking in late summer/autumn. Song output varied amongst passerines, with large seasonal effects in 6 European introduced species, but lower seasonal effects in 9 native species.
We report Records Appraisal Committee (RAC) decisions regarding Unusual Bird Reports received between 1 January 2013 and 31 December 2014. Among the 126 submissions accepted by the RAC were the 1st New Zealand records of buff-breasted sandpiper (Tringites subruficollis) and dusky woodswallow (Artamus cyanopterus), the 2nd accepted record of American golden plover (Pluvialis dominicus), and the 3rd accepted record of Franklin’s gull (Larus pipixcan). Other notable records included a breeding record of white-winged black tern (Chlidonias leucopterus) from Marlborough, the 1st accepted records of little black shag (Phalacrocorax sulcirostris) from Stewart Island and the Snares Islands, the 1st accepted records of nankeen night heron (Nycticorax caledonicus) and Australian coot (Fulica atra) from the Snares Islands, and the 1st accepted record of eastern curlew (Numenius madagascariensis) from Campbell Island. In addition, notable influxes of Pacific heron (Ardea pacifica), little egret (Egretta garzetta), glossy ibis (Plegadis falcinellus) and white-winged black tern occurred during 2013-14. The RAC also reconsidered New Zealand’s only previously accepted sighting of black falcon (Falco subniger, reported from Gisborne in 1983), and determined that the record can no longer be accepted and that this species should be removed from the New Zealand list.
The hihi (Notiomystis cincta) is a small threatened passerine endemic to New Zealand, for which few methods are known for ageing and sexing wild unbanded individuals. We monitored hihi on Tiritiri Matangi Island over 3 years, studying moult and other sexing and ageing techniques. Juvenile hihi before their first partial moult can be sexed by the white bases of primary coverts on males, which appear brown in females. After juveniles undergo their first partial moult, they appear similar to adults; however juvenile males retain old feathers in their primary coverts, alulae, or sometimes greater coverts or inner primaries, while adults undergo a complete moult. These patterns can be difficult to see in juvenile females, but wear of juvenile tails is much greater than in adults at any given time of year, making ageing of females reliable. Moult in the outer primaries and secondaries in autumn also indicate adult birds. This information should help inform future translocations and attempts to monitor viability of wild populations. Finally, we also comment on alternative definitions for ageing criteria from Melville (2011), based not on suspected birth-dates, but on appearance of plumage in hand.
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.
Weights and measurements of 120 male and 109 female adult and juvenile Australasian shovelers (Anas rhynchotis) were obtained from fresh specimens shot in May, mostly during 1976-1979, at 2 sites in North Island, New Zealand. Mean weights of adult males (634 g) and juvenile males (616 g) were significantly greater than those of adult (608 g) and juvenile (558 g) females. For both sexes, weight/tarsus length2 ratios of juveniles were significantly lower than adults but there was no difference between sexes within each age class. Measurements of bill length and width, tarsus and mid-toe-and-claw, and wing and tail lengths are presented for each sex and age class. All measured characters of juvenile males were significantly longer than juvenile females and adult males were significantly longer than adult females. Within each sex, only wing and tail lengths of adults were significantly longer than juveniles. These findings are typical of other shoveler species.
Both apparent annual survival and population composition were estimated, by age and sex, for bellbirds (Anthornis melanura) from a banding study undertaken on a mainland lowland farm at Pleasant Valley, near Geraldine, New Zealand, during the period 1977-97. The model with the fewest parameters showed that apparent survival varied little between sex and years. Although based on only a few recaptures of subadults, apparent survival of adults (0.694 ± 0.042) was slightly greater than that of sub-adults (0.662 ± 0.128). Annual recapture probabilities of adults (0.104 ± 0.024) were also greater than those of sub-adults (0.042 ± 0.029). A comparison of survival and sex ratios between this population of bellbirds and that on the predator-free Poor Knights Islands showed that demographic parameters vary within this species. The mainland population exhibited a lower overall adult survival rate and more even sex ratio than did the island population. Such demographic variation within a species indicate habitat-specific population parameters.
The minimum population size of Kermadec parakeets (Cyanoramphus novaezelandiae cyanurus) is reported for Macauley Island in the southern Kermadec Islands group. To minimise population impacts of any accidental parakeet deaths the confirmed presence of a minimum population of 3,000 parakeets was required prior to the attempted eradication of Pacific rats (Rattus exulans) from Macauley Island. Eight pre-defined vegetation strata were identified and 4 count methods ranging from simple counts to distance sampling were assigned to each strata depending on sampling conditions. As the resultant point estimate of 3,484 parakeets during the 29 June to 1 July 2006 survey period was greater than the minimum threshold the rat eradication was able to proceed. The potential impacts of changes in the vegetation on the population dynamics of Kermadec parakeets and recommendations for future monitoring of this species on Macauley Island are discussed.
The breeding ecology and reproductive traits of brown booby (Sula leucogaster etesiaca) were studied in Gorgona Natural National Park, Colombia. Adult morphometrics, egg dimensions, chick growth and nesting site characteristics, were examined at 3 locations in the park. As with other subspecies, brown boobies in Gorgona exhibit reversed sexual dimorphism. The female booby reaches about 80 cm in length, its wingspan measures up to 150 cm, and they can weigh up to 1,300 g. The male booby reaches about 75 cm in length, its wingspan measures up to 140 cm, and they can weigh up to 1,000 g. First-laid eggs were heavier and bigger than second- or third-laid eggs. Growth of brown booby chicks fit a natural log equation: body mass (g) = 0.8773 ln * days + 3.3895. A variety of nesting aggregations was found, and their relationship with the other marine birds nesting in the area is discussed.
Over 100 Hutton’s shearwater (Puffinus huttoni) nestlings were translocated to the Te Rae o Atiu colony on the Kaikoura Peninsula in February and March 2013. Passive integrated transponder (PIT) tags were implanted in all translocated nestlings and their movements were monitored using both visual observations and recording devices at nest-box entrances. Once nest-box entrances were unblocked about 5 days after birds were translocated, 29 nestlings were resighted 81 times outside their home nest-boxes either in the open (14 nestlings) and/or other nest-boxes (29 nestlings). From the PIT tag records, 37 birds were observed visiting at least 49 nest-boxes on 109 occasions. The most mobile bird made 15 visits to 12 other nest-boxes over 9 nights; another bird visited 6 boxes in one night; and 1 box had 3 visitors in a single night. Nestlings moved within the colony in the period between 1 and 16 nights before fledging, with an average of 8 nights with movement before fledging. The PIT tag readers also showed that the use of pins outside nest-box entrances to determine movements can be misleading as pins were moved up to 13 nights before the nest-box occupant emerged, the pins being moved either by visitors to the nest-boxes or by nestlings wandering past the entrance.
Three hundred and eighty one sooty shearwaters (Puffinus griseus), 2,209 New Zealand white‑faced storm petrels (Pelagodroma marina maoriana) and 14,546 fairy prions (Pachyptila turtur) were banded at Motunau Island, Canterbury, South Island, New Zealand between 1960 and 1999. One sooty shearwater was recovered off the coast of Washington State, USA and 4 others off Motunau Island; the oldest sooty shearwater recovered was found near Taieri airport over 23 years after banding as an adult. Only 1 white-faced storm petrel was recaptured away from Motunau Island and that was found alive on Pitt Island, Chatham Islands. The oldest white-faced storm petrel recovered was found alive on Motunau Island nearly 13 years after banding. Fourteen fairy prions were found on New Zealand’s east coast between Brighton Beach, Christchurch, and Hikutaia near Thames. One fairy prion from Stephens Island and 2 from The Brothers were found at Motunau Island; one was the oldest bird recovered at over 21 years since banding as an adult. Estimates of population sizes based on recapture numbers were 300 for sooty shearwater, 1,300 for white-faced storm petrel and 50,000-60,000 for fairy prion.
Twenty five bird species were recorded following 2 brief winter visits to the southern Kermadec Islands during 2002 and 2006. Of these, 15 were seabirds and 10 land or shorebirds. Rapid changes in the dominant vegetation cover occurred between 1988 and 2002. Ferns replaced grass and sedge swards over much of the island, and although this succession was rapid, the distribution of woody species (the presumed historical dominant cover) did not change, most likely due to limited seed sources, Pacific rat (Rattus exulans) predation, and competition for space from other species. Possible impacts of these changes on the avifaunal composition of Macauley Island are discussed. Following the presumed eradication of Pacific rats from Macauley Island in 2006, recommendations are made for future vegetation and bird monitoring.
The field identification of the orange-fronted parakeet (Cyanoramphus malherbi) has been a problem since the species was first described in 1857. Separating this critically endangered species from its more common, but also declining sympatric relative, the yellow-crowned parakeet (C. auriceps), can be difficult, as both species are cryptic and phenotypically similar. To develop criteria for consistent identification, we assessed >2,700 field observations on the orange-fronted parakeet and >10,000 field observations for the yellow-crowned parakeet, where the phenotypes of each bird was compared to the traits of the genetically defined species and verified type specimens. Observations on 117 nests also allowed observations of young from nestling to independence. We concluded that only 2 field marks can be used to reliably separate the 2 species but a clear view of either the frons or rump patch must be seen. The orange-fronted parakeet has an obvious orange frons and rump patch while these areas on the yellow-crowned parakeet are crimson. No other field traits consistently separated the 2 species. Even then, identification can be unreliable when observing juveniles, when light conditions are poor, or if the bird is high in the canopy. We recommend that unless the observer sees a clear and obvious colour in the frons or rump patch, then that bird must remain as unidentified to species.
The monitoring of endemic birds during the control of introduced mammalian predators is a common practice at community-based conservation projects in New Zealand. We describe long-term trends of endemic passerines monitored using the presence-absence technique during the control of stoats (Mustela erminea) and brushtail possums (Trichosurus vulpecula) in the Flora Valley, near Nelson, New Zealand. Data collected over an 8 year period by Friends of Flora, a community-based organisation, suggests that bellbirds (Anthornis melanura) significantly increased, while South Island robin (Petroica australis), tomtit (P. macrocephala) and rifleman (Acanthisitta chloris) populations showed little or no change, and grey warblers (Gerygone igata) significantly decreased. All species showed a greater increase during the first 4 years of the survey compared to the second 4 years, which suggests that meso-predator release of rats may have occurred from ~4 years after the start of the surveys. The presence-absence technique is simpler to conduct than the more commonly used 5-minute bird count method, and thus may be better suited for use by the community sector in similar situations.