Kawau pāteketeke | New Zealand king shag (Leucocarbo carunculatus) nest occupancy, breeding, and offspring survival was studied for the first time at four colonies in 2018 and 2019, by analysing field camera still images. Nesting territories were retained year-round. Nest-building was underway by Mar and observed through much of the year. Successful pairs with stable nests were elevated and central to nest areas. Inter-colony asynchronous first clutches occurred over six months, with laying spanning 5–10+ weeks at single colonies (2019). Clutches of 2–3 eggs took ≤13 days to complete. Incubation commenced with first eggs; asynchronous hatching was 28–32 days later with brood reduction at early nestling stage and occasional replacement clutches observed. Chicks were unattended at 3–4 weeks, showing strong creche behaviour thereafter, and were fully feathered at 65 days, fledging soon after. Breeding outcome was most influenced by height above sea-level (waves), exposure (weather), and boat/landing disturbance. Most young disappeared from images at 4.5–5 months, their fate—dispersed or perished—unknown. Some resided at the colony into/ beyond the subsequent breeding season, sometimes interacting with presumed parents. Any predation (by gulls) was seen as opportunistic during disturbances, or of eggs not in nests.
Abstract: A new colony of the endangered Hutton’s shearwaters (Puffinus huttoni) has been established at Te Rae o Atiu on the Kaikōura Peninsula, South Island east coast, New Zealand to provide insurance against catastrophic events at the high-altitude natural colonies in the Kōwhai River and Shearwater Stream, Seaward Kaikōura Range. The translocation of 495 chicks from the Kōwhai River colony was carried out in six operations from 2005 to 2013. Of the 473 fledglings, 97 have been recorded back at Te Rae o Atiu. Chick selection criteria, fledgling mass, fledgling wing length, days present before fledging, and days of emergence before fledging had no bearing on whether chicks returned from their post-fledging migration to Australian waters or not. One hundred and twelve Te Rae o Atiu bred chicks have fledged up until 2020–21. The Te Rae o Atiu fledglings had similar mass and wing lengths, and days emerged prior to fledging, to the translocated fledglings. There were no differences between the groups of Te Rae o Atiu bred birds that returned or did not. At 2020–21, 21 of the 112 second-generation chicks have returned from their initial migration, and the earliest have bred successfully. The colony has grown to about 75 birds producing about 30 eggs, 24 chicks, and 22 fledglings annually. Future growth of Te Rae o Atiu will be reliant on these home-bred chicks as the oldest translocation birds will soon be approaching the end of their breeding lives. Acoustic attraction of birds flying over Te Rae o Atiu from the sea towards the Kōwhai River natal colony has been mostly unsuccessful with only two birds attracted.
Abstract: Captive facilities across New Zealand strive to mimic natural conditions for captive animals as closely as possible. In the case of the kiwi (Apteryx spp.), captive habitats are augmented with natural stimuli such as soils, leaf litter, bark, plants, logs, and mosses. Interaction with these introduced stimuli has been shown to encourage normal foraging behaviour and is speculated to aid in inoculating young animals with healthy microbial communities. However, introducing non-sterile natural stimuli into the captive environment also carries the risk of exposing kiwi to diseases such as aspergillosis, coccidiosis, and candidiasis. Aspergillosis is of particular concern to rearing facilities – the disease is most commonly attributed to exposure to Aspergillus fumigatus, an opportunistic fungal pathogen. Here we present a PCR-based screen to qualitatively detect the presence and/or absence of A. fumigatus in soils. Soil samples collected from nesting sites of rowi (Ōkārito brown kiwi, Apteryx rowi) in the Ōkārito region of the West Coast were screened for A. fumigatus using a species-specific primer set coupled with a basic DNA extraction. Willowbank Wildlife Reserve soil and substrate samples were also screened as a baseline comparison representing captive rearing facilities. Results from the assays showed that the extraction technique was effective at isolating A. fumigatus DNA at detectable levels from a variety of soils, and that Ōkārito soils did not harbour a higher abundance of A. fumigatus than those found at Willowbank. This preliminary screening method could be used by facilities in New Zealand to quickly and cheaply screen soils and substrates for A. fumigatus before introducing them to captive enclosures.
This is Part 4 of Volume 70.