The Banded Rail

Gallirallus philippensis

Moho pereru

The banded rail is a handsome little bird, with bands of orange and white worn like a mask across it’s red eyes, an underbelly of striped black and white feathers, a flourish of orange at the chest, and a stippled cloak of olive brown, black and white. Chicks are black and fluffy, and seen in Summer and Spring.

banded rail

Photo credit, Toby Hudson

Banded rail live in wetland, in rough pasture, and on Rakino have also been spotted down at Maori Garden Bay, foraging around the spring that runs down to the bay. They are typically quite cryptic, and seldom forage more than a few meters from the edge of vegetation. You are most likely to see them at dawn and dusk, as they prefer to spend most of their time undercover, hunting for food. They are competent fliers, but prefer their feet on the ground, and can often be seen scuttling for cover, if you are looking..

They eat a variety of insect species, worms, snails, spiders, crabs, but will also tuck into seeds, fruit, and dead fish if they are available.

Threats to the little rail are numerous, and sadly they are declining in number. Their habitat is at risk as people remove wetland and mangroves in favour of pasture and marinas, and they are also at risk from the usual introduced predators; rodents, mustelids, and feral cats. Happily this isn’t a problem on Rakino, as people restore wetland and replant habitats, and we are also extremely fortunate to be free of the aforementioned predators.

A few people on Rakino are lucky to have banded rail living on their properties, and want to prevent them from coming to harm. You can help protect banded rail by keeping dogs on-leash around areas where banded rail nest and forage, and also ensuring cats are under control.

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Auckland Tree Weta

Hemideina thoracica

The tree weta is guaranteed to evoke a strong response in most people who encounter them. They have barbed legs, overlapping amourmed plates on their backs, fierce mandibles, ovipositers that resemble large stingers, and an ability to jump a considerable distance. When threatened they will throw their back legs over their heads in attempt to intimidate their foe by looking larger and spiky, and make a rasping noise by rubbing their legs against their abdomen. The males have a particularly fearsome visage, in the form of an over-sized head which resembles a horse’s, and will also hiss menacingly. In reality, they are mostly harmless, and can make an interesting if undomesticated pet if a weta box is provided as a residence.

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Left to their own devices they live in holes in trees, called galleries. The holes are formed by moth or beetle larvae, or rotted off twigs. A gallery will consist of maybe ten weta, juveniles of mixed sex, females, and one male who rules the harem. The male with the largest head reigns supreme, and it takes three instars to reach maximum head size. Males with smaller heads can mate with females outside the harem, but can also mate with the females of a harem if the dominant males head becomes too large to fit into the gallery entrance!

They are nocturnal, and aboreal, as their name suggests. They feast on soft leaves as a preference, and small insects. They provide a tasty snack for many of our native birds, kiwi, robin, ruru, and tomtit, but are also predated on by the usual introduced predator suspects; rodents, mustelids, hedgehogs, and cats.

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Sand Scarab Beetle

Pericoptus truncatus

mumutawa/ngungutawa

The mumutawa beetle is a sturdy beetle, with an impervious looking carapace and torso, and chunky legs adapted for digging, and rowing through sand. It’s the largest of New Zealand’s native scarab beetles, and is found throughout coastal NZ, above the high tide mark, though it requires a lot of dampness to stop it dehydrating and dying. A nocturnal beetle, it emerges of an evening to fly and wander about in a blundering fashion, on the lookout for food and likely mating partners. The traces of their nocturnal ramblings can be observed in the sand trails they leave behind them.

sand scarab

The female beetle lays her eggs deep in the sand; larvae have been found living more than a meter underground, feasting on the roots of marram grass. They have a tendency to be parasited on by an exotic wasp in Northland, which stings, paralyses, and lays eggs in the hapless larvae. The eggs hatch, and the wasp larvae feast on the mumutawa larvae.

The beetle larvae have been seen perambulating down to the low tide mark at night to cover themselves in salt water. It is posited that this may kill some parasitic mites.

The Pericoptus truncatus was the first beetle collected in New Zealand by Joseph Banks in 1769.

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Little Blue Penguin

Eudyptula minor

Korora

There are 18 species of penguin worldwide, and 9 of them breed in New Zealand territory. The korora is the smallest of that unique species, 30cm high, and the only flightless seabird you are likely to see in the Hauraki Gulf.

korora

They spend their days out at sea in search of small fish, squid, and octopus, coming ashore at night in convivial little groups called ‘rafts’, to roost.

On Rakino Island, some fortunate residents have korora nesting under their baches, or sheds, though they may debate the description ‘fortunate’ when they are kept awake at night listening to the squabbling of little penguins!

Little blues come ashore between January and March and must spend two weeks moulting, replacing all their feathers before they can head out to sea again. They are very vulnerable at this time to dogs, so this is a good time to ensure our dogs are on-leash in known penguin areas.

If you see a listless, scruffy little penguin at this time, just give them a wide berth, and leave them to get on with moulting.

The biggest threat to korora on land are introduced mammalian predators; rats, mustelids, feral cats, and dogs. Happily Rakino is predator free, so to keep the korora safe, we only have to ensure that cars drive slowly and carefully at night, when penguins may be on the roads, and that our island dogs are under control, and leashed when penguins might be in the vicinity.

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Eyrewell Beetle

Holcaspis Brevicula

Status; extinct

Only ten Eyrewell beetles have ever been found. No more will be found, as their habitat of kanuka and exotic pine trees has been replaced by 14,000 cows, at the behest of Ngai Tahu, in a dairy conversion that happened in 2019. DoC attempted to work with the owners of the land to ensure some protections for the small black carabid beetle, but were ignored. Unfortunately our conservation laws do not extend to private property, unless the endangered flora or fauna at risk is protected under the Wildlife Act.

eyrewell beetle

The Eyrewell beetle was threatened from the outset, when it’s kanuka habitat was destroyed to make way for exotic pine plantations, the eponymous Eyrewell Forest. It survived on to exist in 7000 hectares of pine, but when the pine forest was returned to Ngai Tahu in 2000, the beginning of the beetles’ obituary was written.

Small, black, flightless, and un-charismatic, the beetle had no chance of prevailing when pitted against the prospect of income generated from the sale of milk powder and infant formula, grown off the back of a center pivot irrigation system, fed by the Waimakariri River, in a traditionally dry region of Canterbury.

The Eyrewell beetle was about 1 cm long, shiny black, nocturnal, and couldn’t fly, though it could run, but not fast enough to outrun the shredders that chipped the pine trees up into sawdust so fine any creature larger than a pinhead could not survive. It’s tenacity that ensured survival of it’s earlier habitat destruction could not survive this final blow.

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Cromwell Chafer Beetle

Prodontria lewisii

Critically endangered, this small, flightless, unremarkable, brown beetle has a habitat of 81 hectares in the arid Cromwell basin of Central Otago. It was never a habitat larger than 500 hectares, and the construction of the Clyde Dam and resulting Lake Dunstan combined with land repurposed for housing development and a golf course has eaten up more than 80% of their original habitat.

cromwell chafer beetle

The remaining habitat is under threat from the ravages of the Australian Redback spider, an unwanted import who makes it’s home in the abandoned rabbit burrows that litter the sandy loam the chafer beetle lives in. The Redbacks build a web in the empty holes, and repurpose them as a nursery for baby red-back spiders. Apparently one enterprising Redback had preyed upon 70 chafer beetles, as evidenced by the midden of crispy beetle husks piled in his lair. Chafer beetles are the second favourite prey of the Redback, after the darkling beetle.

Department of Conservation staff have been gingerly removing Redbacks from the former burrows with long-handled tongs, and then infilling the holes. This seems to be an effective solution for dealing with the spider problem.

Every December a chafer beetle larvae count is carried out by DoC staff, under the brutal Central Otago sun. More than 600 soil cores are removed from the earth, and hand-sifted through by the participants, in the hope of finding the elusive little grubs. The numbers found are generally very low, maybe just a few individuals. The beetle population is estimated to be about 3000. Cromwell chafer beetle larvae spend many months buried in the sand chewing through tussock roots. They go through three phases of instar before pupating for three months. When the adult beetle finally metamorphoses, it spends it’s days burrowed up to half a metre underground, before emerging on spring and summer evenings to mate, and feast on scabweed.

I don’t know if the Cromwell chafer beetle will survive all the threats it faces. It’s difficult to feel hopeful.

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Robust Grasshopper

Brachaspis robustus

The Robust Grasshopper lives only in the Mackenzie Basin in the South Island of New Zealand.

Absurdly endangered, predator proof fencing has been erected around it’s arid habitat in the hope of protecting it from it’s main predators, hedgehogs, stoats, and feral cats. It is also being raised in captivity.

robustgrasshopper

Photo credit, DoC

If  you were to ask me, I would probably tell you it is my favourite insect. If we all had a favourite insect, they might be less likely to succumb to extinction. Alas, insects are the everyday invisible, the creatures that teem around you that you fail to notice till they are gone.

Brachaspis robustus is a handsome creature, armoured like a tank, with the physique to match. An image of the male mating the female is reminiscent of a Sherman tank with gun turret resplendently mounted, such is the sexual dimorphism between the sexes. The female is considerably larger, at 38 to 42 mm in length, the male about half her size.

Their wings are mere nubs unsuitable for flight, and they tend to freeze when spotted by a predator, so they rely on camouflage to save their exo-skeletons. They can adapt their colour to their environs, colours ranging from a rusty brown, through to gun-metal grey, and less commonly black.

The males can jump quite well, with the ability to jump up to 1.5m with frequency in warmer weather, but they are very poor at landing, and will often land badly, on their backs, or bellies, with a sorry thud. The bulky female is a poor jumper. None of these things add up to an especial ability to save themselves from predation.

There are maybe 600 robust grasshoppers, and they live about two years, so sucessful breeding without predation is vital to preserve the species. Egg-laying season is Summer through to Autumn, two clutches of eggs of 20 to 30 eggs a clutch. They seem to be able to cope with extremes of temperature, such is the harshness of their environment, and it’s likely their eggs require very cold temperatures to hatch, and the nymphs winter over before emerging as an adult in Summer. The adults are observed to be promiscuous copulaters.

They are herbivorous, feeding on various mosses, lichens and herbs found in the vicinity of their rocky drought-prone home, moisture and succulence being at a premium in their diets. Apparently they will happily devour a dandelion snack within minutes.

I feel cautiously hopeful for their survival knowing that a conservation project successfully raised $130k to erect a predator fence to protect them, and that Canterbury entomologist and conservationist Tara Murray has a team dedicated to their study and species continuation. Changing climate could present an inescapable problem however, if the eggs can no longer get the freezing conditions they need as a hatching signal.

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Mokohinau Stag Beetle

Geodorcus ithaginis

A sea stack in the Mokohinau Islands known only as ‘Stack H’ may or may not be the last remaining home for our rarest beetle. Their habitat is the size of a generous living room; they have been predated out of existence everywhere else. They are so extraordinarily rare that their home can’t be revealed as unscrupulous poachers and collecters of endangered and precious creatures could feel compelled to liberate these beetles from their remote sea stack.

StackHbeetle

They are a good-sized beetle, the males up to 32mm long, the females slightly smaller, pleasingly stocky, flightless, and a slow perambulator, which is fortunate, because there is nowhere much for them to go on Stack H. The males have a protruding mandible used for battling other males for beetle supremacy.

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Stag beetles are under threat worldwide, mainly because of habitat loss. It takes a long time to become a stag beetle; they live as larvae underground for years before briefly becoming a beetle, and require a stable habitat of rotting logs and leaf litter in order to ensure their survival. The Mokohinau stag beetles do not have the luxury of leaf litter on their stack. They live amongst the peat-like substance that forms beneath the New Zealand ice plant, in tussock plants, and under rocks. Only rugged, sea-battered pohutukawa provide fallen leaves for beetles on Stack H.

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At the start I mentioned that Stack H may not be the last remaining home for the Mokohinau stag beetle… this is not because they may have another as yet undiscovered home. Unfortunately a recent attempt at a stocktake of the beetle numbers was an abject failure. Not a single beetle was located, despite repeated fruitless searches. Quite simply, there was no evidence of the beetle to be found. There is a slim possibility that there are some as yet unmetamorphosed larvae underground, and something has befallen the adult population, but more likely they have disappeared forever, another victim of habitat loss and predation by introduced species.

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