Motukiekie Rocks

The Motukiekie Shakedown will also protect the offshore Motukiekie Rocks – probably the largest cluster of unmodified sea stacks and islands on the West Coast, and home to fairy prion, spotted shag, red billed gull, blue penguin, southern black-backed gull, variable oystercatcher, and other seabirds.

The Motukiekie Rocks lie directly offshore from the management area, and will be protected from rat and stoat invasion from the mainland.

A survey in 1999 (D Neil) recorded seabird burrows on most of the eleven islands, with an estimated overall total of several hundred burrows. A fairy prion was found in a burrow, and it is likely that most or all of the burrows belong to this species.

Fauna Key Species

Birdlife

Bush birds currently present:
Great spotted kiwi, kea, bellbird, fantail, tui, weka, rifleman, fernbird, tomtit, New Zealand pigeon, yellow-crowned parakeet, New Zealand falcon, grey warbler, chaffinch, silvereye, blackbird, morepork, welcome swallow, Australasian harrier, South Island robin, shining cuckoo, house sparrow, song thrush, brown creeper, New Zealand Pipit, kaka.

Seabirds currently present:
Blue penguin, spotted shag, red billed gull, fairy prion, sooty shearwater, southern black-backed gull, variable oystercatcher.

Kaka (Nestor meridionalis)
Kaka are large, forest-dwelling parrots who can be found in a wide variety of native forest types including podocarp and beech forest. With probably fewer than 10,000 birds, the biggest threat to their survival are introduced mammalian predators, particularly the stoat, but also the brushtail possum. Kaka mainly breed in spring and summer, and nests are generally in tree cavities over 5 metres above the ground. In November 2017, a flock of six kaka were observed flying and calling over Motukiekie settlement northbound. In November 2019, a kaka was heard in the northern section of the management area, and in January 2020 two kaka were seen and heard near Firebase Cobra. It is not known if they are resident.

Sooty shearwater (Puffinus griseus)
A small number of sooty shearwater have been seen and heard circling above the 12 Mile bluffs and trig station A8NK, after dark and early morning, from early November to mid-February. Seabird calls were heard on the ground (possibly burrow calls), during the day on Whiteman’s Terrace in early December 2017, indicating that a population may still be nesting on the mainland. Historically, a colony of “seabirds” nested on the headland around trig station A8NK (locally known as “Starvation Point”), until they annoyed neighbours so much that the headland was burnt in the early 1940s.

Kea

Kea (Nestor notabilis) are endemic to the Southern Alps of New Zealand and are the world’s only mountain parrot. With only a few thousand birds remaining, the kea is a Nationally Endangered species. Territories are extensive and can cover up to 4kms² (Jackson, 1969; Elliott & Kemp, 1999). In January 2017, one kea was heard flying through the headwaters of Kararoa Creek. Anecdotal reports from hunters and possum trappers of hearing kea regularly in the same area since 2014, are encouraging.

In November 2017, a kea was observed close up sitting and calling on Mt George. In September 2018, a kea was seen flying and calling south of Mt George, southbound across the 10 Mile Creek. In October 2018 residents at Kararoa Creek reported hearing a kea in the watershed.

Roroa Great Spotted Kiwi

Roroa/great spotted kiwi (Apteryx maxima) inhabit c. 800,000 ha of remote, generally mountainous habitat in the top half of the South Island of New Zealand, where they form four genetically distinct populations: Northwest Nelson, Westport, Paparoa Range and Arthur’s Pass–Hurunui.

There are an estimated 14,000 roroa left in the wild, and the species is thought to be declining at a rate of 1.6% per annum across its range. Effective mustelid predator control has shown to lead to a 5.6% roroa population increase.

Roroa/great spotted kiwi (Apteryx maxima) species plan 2019–2029

In October 2016, kiwi beak probe holes were found, some only 40 meters from the Motukiekie settlement, and kiwi calls were heard. Subsequent monitoring has confirmed four kiwi pairs. This is very exciting news, especially after many years of anecdotal reports and speculation. Assuming a mean density of 1.5 pairs/km² (McLennan and McCann), there may be up to 12 pairs living within the management area.

*Whio Blue Duck

Historically, whio would have inhabited the Ten Mile Creek/Waianiwaniwa, a mountainous bush river flanking the eastern side of the Motukiekie Shakedown. It’s likely that a population remains in the mid to upper reaches, or that whio from the eastern side of the Paparoa Range have migrated back into the Ten Mile from the DOC whio program in the Moonlight Creek area.

Whio on the West Coast generally have quite large territories (~1-2km) and the Ten Mile Creek could sustain a couple of breeding pairs.

One blue duck was seen in the lower section of the 10 Mile Creek in March 2020 (misc. comms. DOC). A blue duck was observed by locals in nearly the same pool in the 1980s. Conversations with residents suggest there was an abundant population of whio in the 70s and 80s. Requires further investigation.

New Zealand long-tailed bat

Bats are New Zealand’s only native land mammal and is ranked as Nationally Critical. Chestnut brown in colour, they have small ears and weigh 8-11 grams. They are believed to produce only one offspring each year. They can fly at 60kph and have a very large home range (100km²). An aerial insectivore, they feed on small moths, midges, mosquitoes and beetles along bush edges. Female long-tailed bats congregate in maternity roosting trees with their young during the summer breeding season. They usually move roost tree every night.

Bats use dead and old trees with hollows and cavities to rest by day and breed in cavities in old-aged trees. They move to a new roost tree regularly so are not always present at a site, but may return later to reuse it. A social group can use over 100 different roosting trees.

“Bats require specific conditions: near a water source – creeks, gullies, streams. Open areas – forest edges. Big mature trees. Warm nights – November to April. Uses Magenta Bat 5 bat detector.” (Ben Paris, NZ Batman).

Flora Key Species

Celery pine (Phyllocladus alpinus), spider orchid (Singulary oblongus), northern rata (Metrosideros robusta) and southern rata (Metrosideros umbellate) and black beech (Fuscospora solandri). Small stands of black beech occur at Motukiekie, seemingly well outside its normal distribution range (Wardle 1969).

At altitude, there are large areas of yellow silver pine (Lepidothamnus intermedius), and in the forest there are many orchid species, including spider orchid (Corybas sp).

Red mistletoe (Peraxilla tetrapetala) has also been found which is classified as “At Risk – Declining”.

Pest weeds around the Motukiekie settlement include Elaeagnus, Wild ginger and bamboo.

Predator plague cycle during a masting year

Predator Fun Facts

Ship rats (Rattus rattus), stoats (Mustela erminea) and possums (Trichosurus vulpecula) are the most significant predators present in Motukiekie, as well as the occasional feral cat.

Ship rats

Ship rats probably travelled to New Zealand on board European ships in the 1800s; they then spread through the North Island sometime after 1860 and through the South Island after 1890 (Atkinson 1973). Historically, ship rats, Norway rats (Rattus norvegicus) and kiore (Rattus exulans) were all important predators of native wildlife; however, ship rats are currently by far the most widespread, common and significant of these three species of rat. They are also agile climbers and are ubiquitous in forests on mainland New Zealand, where they can reach plague numbers following beech (Lophozonia spp.) and rimu (Dacrydium cupressinum) mast events (Harper 2005; Innes 2005). As arboreal and omnivorous predators, ship rats prey on the eggs, nestlings and adults of native birds, as well as lizards, bats, frogs and land snails. They eat about 15g of dry food a night (10% of body weight).

Scarce in pure silver or mountain beech forest and very rare at high altitudes (above c.1000m asl). An agile and excellent climber, but a poor swimmer. Can spend considerable portions of time foraging up in trees.

Gestation 21-23 days, the litter size averaging 5-6. The young are mobile after 1 month and completely independent and sexually mature after three months. Females can produce three or more litters annually in a breeding season which can be 6-7 months or longer. Mortality rate is high, with few rats (<10%) surviving more than one year.

Home range is variable but usually between 0.5–4 ha (diameter of 100-200m) and densities can also vary widely but is on mainland sites usually 1–3 per hectare, though up to 6.2 per ha has been recorded. There can be substantial overlap in ranges of individuals within and between sexes.
Males range up to 300m (mean 194m), females up to 100m.
They know their neighbours well and if one is removed, invaders take over the empty range within days. In a study, the rats used 3-4 daytime nests over a 5 week period. Variable amounts of time are spent in each nest.

More ship rat information

Stoats

Stoats were introduced to New Zealand in 1884 to control rabbits (Oryctolagus cuniculus) (King & Murphy 2005), and are now ubiquitous in North and South Island forests and other habitats (Smith et al. 2007). Although stoats do not reach the same densities as ship rats, they are highly mobile with large home ranges and, unlike ship rats, are obligate predators rather than generalist omnivores (King & Murphy 2005). They are also semi-arboreal and capable of killing prey many times their own weight. Stoats hunt at any time, day or night.

A single litter is produced annually of up to 12 kits (mean 6–8), from late September (northern areas) to late October (cooler climes). Den sites are well hidden and changed frequently. Young are independent from early January. Nearly all females leaving their natal nest are already pregnant but delay development of the fertilised eggs until the following spring.

They have excellent powers of dispersal and individual juveniles have been known to travel over 70km in two weeks. They are also strong swimmers, known to have crossed water gaps of up to 1.1km to reach islands.

Main foods are rodents, birds, rabbits, hares, possums and insects, particularly weta. Lizards, freshwater crayfish, carrion, birds, eggs, hedgehogs and fish are also taken. Can eat 1/4 of their body weight a day.

Most stoats (>80%) live less than one year, but adult mortality is lower, and a few may reach 5–8 years of age.

Home range
Males often > 200 ha and females often > 100 ha. Although home ranges overlap, particularly between sexes (Erlinge & Sandell 1986; Murphy & Dowding 1994; 1995; Alterio 1998), it appears that many individual stoats have separate core ranges that do not overlap (Murphy and Dowding 1995; Young 1999).
Stoats tracked during the summer had very small home ranges (males 16.0 ha, females 9.4 ha), and with the exception of two immature animals, were defending intrasexual territories. Two males tracked in the spring had larger home ranges (47.9 ha) and were not territorial. (Cuthbert & Sommer 2002).

Density
Stoat density on Resolution Island (20,800 ha) in Fiordland, was estimated to be 1.4 stoats per km².
Alterio et al. (subm.) estimated absolute density of stoats in a South Island beech forest as 4.2 stoats km² (95% C. I., 2.9-7.7 stoats km²) for the summer period and 2.5 stoats km² (95% C. I., 2.1-3.5 stoats km²) for the winter period.
Original stoat density on Adele Island was about one per 9 ha before trapping was started.

“Stoats are shy of tunnels and devices”. “A dying rat is irresistible to a stoat”. “It is large populations of rats and mice that determine the number of stoats in an area”. “Stoats can’t survive long without mammalian prey. Rats, mice, possums and rabbits provide the most meat in their diet. If you remove them, stoats will eat a lot of birds over the short term, but they can’t maintain a large population long-term only on birds.” (Prof Carolyn (Kim) King 2016).

Possums

Brushtail possums were intentionally introduced to New Zealand to establish a fur trade and were successfully established by 1858 (Cowan 2005). They now occur throughout the main islands, although they have only recently colonised Northland and south western Fiordland. Like ship rats, possums are ubiquitous in forests, are agile climbers and can reach high densities (eg. 10–12/ha) (Cowan 2005). Although possums are primarily herbivorous, they opportunistically prey on native wildlife (Brown et al. 1993; Innes 1995; Sadleir 2000) and evidence of the impact of such predation on native species has increased dramatically in the last two decades (O’Donnell 1995; Montague 2000). Tennyson & Martinson (2006) suggested that possums possibly contributed to the extinction of South Island kōkako.

✔ COMPLETE

Stage One was a small-scale trapping program of about 12 hectares primarily targeting stoats and rats, and occasionally possums. It was designed as a trial to test different traps and bait types, and see how labour-intensive a larger scale management project might be.

DOC200 humane kill trap boxes (weka-proof) were spaced at 100 meter intervals, interspaced with a TREX rat snap trap. The DOC200 traps were baited with a quartz rock replica egg, and a block of Erayz Dried Mustelid bait. TREX traps were baited with peanut butter, and then Nutella as a trial. Although Racumin (1st generation anticoagulant) was initially used to target rats, there are now no chemical toxins used.

Timms possum kill traps were mounted high on tree branches, or on a length of board placed on an angle against a tree, to keep them out of reach of resident weka.

Stage One was entirely self-funded to the cost of approximately $5,000 in materials, and 500 hours of labour ($12,500).