The distribution and habitat use of New Zealand pipits (Anthus n. novaeseelandiae) in Tongariro National Park on the volcanic plateau of the North I was assessed in Nov 1998 and Mar 1999. Pipits were found at 13 of 22 sites. Surveys between Nov 1998 and Oct 2009 found pipits present all year at Lake Te Whaiau, Mangatepopo Road and Waipakihi Road. Pipits were also seen along the road through the wetland at Erua in winter and summer. At Lake Te Whaiua, pipit presence and use of habitats differed seasonally. The average maximum flock size in summer was 9.7 (se = 1.05, n = 11). Maximum roadside counts outside of the flocking period were 1.13 pipits km-¹ (se = 0.17, n = 5) along Waipakihi Road and maximum summer flock sizes there averaged 6.0 (se = 1.05, range 2 – 18, n = 19) birds.
An updated list of bird species identified at Washdyke Lagoon, Timaru, New Zealand is presented, along with the corresponding threat status and references relating to individual species. The information was based on a literature search of published or readily available information. Sixty-five species were identified (plus hybrids and unidentified species), which expands considerably on previous checklists from the lagoon. Eighteen species (nearly 28%) are threatened or at risk. The number and diversity of species identified emphasises the importance of the lagoon as a coastal wetland habitat on the central east coast of the South Island. The lagoon’s existence is under very serious threat from coastal erosion and a variety of human influences.
Monitoring of breeding success in 2006/07 and 2007/08, and visits in Dec 2007 to assess levels of stoat predation and burrow densities were undertaken in order to assess the status of Hutton’s shearwaters (Puffinus huttoni) at the 2 remaining breeding colonies. Long-term (20 year) estimates of burrow density within the Kowhai Valley show a consistent increase in burrow density within this colony. Along with the discovery of a new area of burrowed ground, these results suggest the population of Hutton’s shearwater has increased in this colony over the last 20 years. Burrow density data for Shearwater Stream are less robust, but does not appear to show a decline. Measures of predation rates in the Kowhai colony show no major differences in the numbers of adult shearwaters found on transects in comparison with the late 1990s and the recovery of shearwater carcasses from burrows in 2 recent seasons also does not differ from the late 1990s. Burrow occupancy levels in both colonies in 2006/07 are similar to the 1990s. In contrast, breeding success in both the Kowhai Valley and Shearwater Stream were very low in the 2006/07 and 2007/08 breeding seasons. Due to the lack of evidence suggesting an increase in stoat predation, these low values of breeding success are hypothesised to be a result of poor at-sea feeding conditions. The apparently consistent lower breeding success at the Shearwater Stream colony (and lack of evidence for alternative local environmental impacts such as heavy snowfall or rain events within this colony) may well be a consequence of stoats, due to the differential impact of stoats at this small colony (8,000 breeding pairs) in comparison to the far larger Kowhai Valley colony (106,000 pairs). Continued annual monitoring within both colonies and a programme of stoat trapping within the Shearwater Stream colony are recommended in order to better assess breeding success and to determine if trapping can protect the smaller colony. Five-yearly monitoring of burrow densities and predation rates should continue to help evaluate long-term trends and the health of this endemic New Zealand species.
An annotated checklist of the birds of Motu Kaikoura (Selwyn Island) in the Hauraki Gulf, New Zealand, is provided from surveys carried out between Dec 2006 and Jun 2008, supplemented by other recent observations. Thirty-seven species were recorded, including 25 species of land or wetland birds, and 12 species of seabirds and shorebirds. A total of 26 species were indigenous and 11 species were exotic. Motu Kaikoura was gazetted as a scenic reserve in 2004, with ecological restoration a key aim of its management. The 564 ha island has low vegetation diversity, reflecting a long history of anthropogenic degradation. Fallow deer (Dama dama), rats (Rattus spp.), mice (Mus musculus) and feral cats (Felis catus) were present on the island. Eradication of invasive mammals has been a management priority, with the bird surveys representing baseline data against which the progress of ecological restoration can be measured.
Tree-cavity nesting is common for a broad range of bird species throughout the world. However, the majority of information on the use of cavity nests is largely derived from the Northern Hemisphere with little data originating from tropical or southern temperate areas. We discuss 3 factors (predation, microclimate, and cavity abundance) that may have shaped the evolution of New Zealand’s tree-cavity nesting birds. New Zealand’s landbird fauna possesses the highest percentage (24%) of secondary tree-cavity nesters (7 orders and 12 families) of any region examined. Given the high occurrence of tree-cavity nesting in New Zealand’s avifauna there may be environmental pressures that select for this form of nesting. Historically, birds were likely the main nest predators of New Zealand’s cavity nesting birds and indications are that nest predation levels are not comparable to some continental habitats. This suggests that other factors such as microclimate or cavity abundance may have played a disproportionate or complementary role in influencing the high percentage of tree-cavity nesting in New Zealand. However, evidence is limited and any attempt to identify selection pressures on tree-cavity nesting must be balanced against phylogenetic concerns, as some birds were likely tree-cavity nesters before their arrival in New Zealand.
Here I report on a small scale study aimed at generating baseline information on the immune response of wild red-fronted parakeets, as assessed by blood cell counts, and subcutaneous challenge with phytohaemagglutinin (PHA), a mitogen that causes swelling at the point of injection. Eleven parakeets captured in mist-nets were injected into the right patagium with 0.5 mg PHA and the resulting swelling measured at 6 hours post-injection. Prior to PHA challenge, feather and blood samples were collected for detection of beak and feather disease virus and Plasmodium. Blood smears were also prepared for blood cell counts. Swelling occurred 6 hours post-injection in all but one individual, which tested positive for beak and feather disease virus. In this individual, no measurable swelling was detected. Estimated leucocyte counts, lymphocyte counts and heterophil counts of the same individual were similar to values of beak and feather disease virus negative individuals. Plasmodium DNA was detected in 2 individuals and their immune response was similar to that of parakeets testing negative for both beak and feather disease virus and Plasmodium. Estimated leucocyte counts, lymphocyte and heterophil counts did not differ between Plasmodium infected and non-infected individuals. The fact that the only individual testing positive for beak and feather disease virus showed no immune response to PHA challenge suggests increased susceptibility to other pathogenic infections. Although preliminary, this study highlights the potential damaging consequences of the accidental introduction of beak and feather disease virus in conservation programmes of threatened New Zealand parrots, some of which might already suffer from decreased immunocompetence resulting from reduced genetic diversity.
Thirty-one North Island weka (Gallirallus australis greyi) were released on Pakatoa Island (26 ha), Hauraki Gulf, New Zealand in Aug 1996. The population then fluctuated between c.19 and 182 individuals, including c.6-55 pairs. The last of the translocated weka died between Jan and Jun 1998, during a drought and after the rodenticide Talon® was laid to kill Norway rats (Rattus norvegicus), and only weka <1 year old survived. Most young raised in Dec 2001-Jan 2002 died during a drought in Feb – Mar 2002. The weka population increased during a period of higher rainfall from mid-1998 to Dec 2001. The higher population resulted in smaller home ranges, higher frequencies of diurnal spacing calls, more aggressive behaviour, and a higher incidence of plumage damage. The large fluctuations in population size on Pakatoa I suggests that future translocations of weka should select islands with wetter and less variable rainfall patterns.
Conservation management of threatened species (single-species management) is likely to confer benefits to non-target native species, although there are few studies. We examined the relationship between the relative abundance of New Zealand pigeon/kereru (Hemiphaga novaeseelandiae), tui (Prosthemadera novaeseelandiae), grey warbler (Gerygone igata), fantail (Rhipidura fuliginosa) and tomtit (Petroica macrocephala), and intensity of mammalian pest control conducted to protect the endangered North Island kokako (Callaeas cinerea wilsoni) in the Hunua Ranges, 40 km south-east of Auckland, New Zealand. Study areas were subjected to either high intensity (Kokako Management Area, KMA) or low intensity (Milne Stream and Rata Ridge) pest control, and we established 17 monitoring stations per study area and conducted 17 x 5-minute point counts of forest birds in all 3 areas. Abundances of kereru, tui, tomtit, were significantly higher in the KMA. Our findings suggest that single-species management targeted at kokako also benefits some non-target native birds. The contribution of single species conservation management to overall ecosystem integrity is not well understood, and further research is needed to improve the ecological value and cost effectiveness of such management techniques.
New bioacoustic technologies offer novel ways to monitor bird populations in the field. Bioacoustic techniques can greatly enhance effective field time, enhance survey site coverage, and increase quantification of key time periods such as crepuscular and nocturnal hours. Moreover, digital files provide searchable, independently verifiable records. Historical impediments to the use of bioacoustics have diminished with unit costs declining and data storage capacities increasing. Recent software developments enable rapid extraction of targeted bird calls and facilitate ease of data analysis. This paper details the recent application of bioacoustic technology at a proposed wind farm site in the upper North I, New Zealand. In this case, bioacoustics were employed as a supplement to on-site field observations and as a complement to avian radar technology. Results illustrate the utility of bioacoustic methods, highlighting the range and scale of potential data outputs. In addition to the detection of flight calls and song, audible wing flap noise may provide a further means of identification for some species. Targeted monitoring of migrant birds, cryptic marshbirds, and rare seabirds are identified as potential future applications.
Bird nests often contain objects produced and manipulated by other animals, including human rubbish. The function, if any, of these items remains unclear, and it is unknown whether they might serve a signalling role to increase the conspicuousness of the nest lining or contribute to its crypsis. We located several nests of the introduced song thrush (Turdus philomelos) in New Zealand containing discarded cigarette butts. These items were embedded into the dried mud-matrix of the nest and appeared visually inconspicuous to the human observer. However, human and avian visual sensitivities are dramatically different. We used full-spectrum reflectance spectrophotometry, combined with perceptual modelling of the avian visual system to assess the contrast between mud lining, garbage, and the colours of thrush eggs. Our analyses confirmed that, when perceived by birds, cigarette butts were similar in appearance to the nest lining and showed sharp contrast with the eggs. We suggest that cigarette butts form an opportunistic structural component of the song thrush nest. It remains to be determined whether human-made objects in song thrush nests serve anti-predator or an olfactory signalling function. This study illustrates the application of avian perceptual modelling to test signalling based hypotheses for the extended phenotype of birds, including nest architecture.
In a 5 year radiotracking study of 55 falcons on the Wairau Plain, Marlborough, the causes of death in 21 birds were identified. Of these, 10 (47%) falcons were electrocuted (7 juvenile females, 1 adult female, 1 juvenile male, and 1 adult male). Seven of the 10 poles were fitted with transformers. This level of mortality is thought to be too high to sustain a population of falcons. Suggestions are made how to mitigate the problem.