Southern Brown Kiwi(Apteryx australis)
They are a shy flightless bird that is only found in New Zealand. They are also known as tokoeka, or common kiwi. It has no preen gland, and its feathers have no aftershafts and no barbules. There are large vibrissae around its gape, and it has no tail, only a pygostyle. It has a length of 45-55 cm and the female weighs 2.1-3.9 kg and the male weighs 1.6-2.8 kg. Its bill is long and slender with a slight down-curve. Like other kiwis it is nocturnal. The colour of its plumage is rufous with some streaking.
The southern brown kiwi is divided into two subspecies:
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A. a. australis, , with a population of approximately 7,000 birds is found on the South Island of New Zealand. A disjunct population, near Haast, called the Haast brown kiwi (not to be confused with Apteryx haastii), is rare (with only about 250 specimens left) and is characterised by its rufous plumage.
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A. a. lawryi, is relatively common (20,000 birds) throughout its range, with about 17 birds per square kilometre. Its feathers are streaked lengthwise with reddish brown.
Habitat
Southern brown kiwi are native to New Zealand. They live in the South Island and Stewart Island. On the mainland (South Island) they live in Fiordland and Westland. These birds inhabit temperate and sub-tropical forests, grassland, and shrubland. They are widespread throughout Stewart Island where they also live on the sand dunes. Their range is Blue on the map adjacent.
Diet
Southern brown kiwi are carnivorous birds. They feed on invertebrates, including earthworms, beetle larvae, snails, spiders, centipedes, grasshoppers, and crickets. They will also consume fallen fruit and leaves.
Breeding
Southern brown kiwi are monogamous and once paired up, they will defend their territories with warning calls. The size of their territory usually ranges between 4.9 and 43 hectares (12 and 106 acres). Nests are made in burrows or sheltered beneath thick vegetation. The female lays 1-2 eggs, typically just 1, which the male incubates for 90 days. The chick is hatched fully-developed (precocial) and after a few days, it will leave the nest. The chick will feed on its own but may stay around parents for a year. Young males become reproductively mature and start breeding at 14 months of age while young females reach their maturity when they are 2 years old.
Population
According to the IUCN Red List, they are classed as Vulnerable(VU). The 2013 total population was estimated at 21,350 birds, down from previous estimates of 27,225 birds in 1996 and 29,800 birds in 2008.The isolated and genetically distinctive Haast population was reported as 225 individuals in 1996, but intensive pest control and ex-situ hatching of wild-sourced eggs and chick-rearing in predator-free crèches, and the establishment of small populations at pest-free mainland and island sites has resulted in a growth to 350 birds in 2013. The species is still common in localised areas in Fiordland (9000 birds) and in central and southern parts of Stewart Island (12,000 birds) but is thought to be declining. Stoat trapping in the Murchison Mountains resulted in a doubling of chick survival, and this turned a population decline of 1.6% per year into a gain of 1.2% per year. In 125 ha of abandoned farmland at Mason Bay, Stewart Island, the tokoeka population dropped from 17 pairs in 1993 to 11 pairs in 2013 (2.2% per year), but it is not clear if this has been driven by recruitment failure through predation of chicks by feral cats, or by habitat loss as flax, tussock and scrub reclaim former grassland feeding sites. The species is common on Stewart Island but is thought to be declining (from 20,000 birds in 1996 to 15,000 in 2008) and in localised areas in northern Fiordland (10,000 birds) and southern Fiordland (4,500 birds). The inferred decline of 5.8% per year on the mainland, like its congener A. mantelli, is now considered to have been much too pessimistic, and the actual rate of decline is thought to be closer to 2%. The generation length used here may need to be revised, with possible implications for the inferred rate of decline.
Threats
The impact of introduced predators is the greatest threat: stoat eat eggs and chicks up to 1000 g, feral cats eat chicks and juveniles up to 1,200 g, and dogs, ferrets, and brush-tailed possums kill juveniles and adults. Predation pressure is possibly lower on Stewart Island where mustelids are absent, and dogs are prohibited from most of the island. However, feral cats are widespread and common. The rate of loss of native habitat has declined markedly and this is not currently considered a driver for population reductions. Avian diseases and pathogens are a potential threat, particularly with chicks held in captivity or in high-density crèche sites. The Haast population is at risk from stochastic events due to the small population size and isolation and suffers from low fecundity.
Conservation
Conservation Actions Underway
Monitoring is nationally coordinated, and uses call-counts, specially-trained dogs searching for banded birds, and radio-tracking. Intensive management involving predator control and removing and incubating eggs and returning subadults once large enough to fend off predators is taking place within the Haast population. The latter approach has been used at Haast since 1995 under the name Operation Nest Egg (ONE), and has succeeded in increasing the population of A. australis Haast. Research has focused on the Haast, Clinton valley, Murchison Mountains and Stewart Island populations, and involves taxonomy, investigating the effects of predators and their management, ecology and the social structure of populations.
Conservation Actions Proposed
Survey populations in Fiordland and undertake population modelling of all taxa. Clarify the taxonomy of the species. Research reasons for low productivity in the Haast population. Evaluate the success of translocations and support the development of a structured captive breeding programme. Intensively manage the Haast population and at least one other mainland population using the ONE programme with the goal of doubling the population. Investigate landscape-scale remote monitoring techniques for sparse populations. Maintain the mustelid-free status of Stewart Island and investigate the possibility of eradicating cats from the island. Promote legislative and policy changes to protect populations and encourage high-quality advocacy at all levels. Educate and inform the public and encourage community involvement in kiwi conservation.