Ten critically endangered critters with the craziest stories

Wednesday, 11 July 2018

The way we think about our native species is changing - slowly.

Once a nation captivated only by our cuddliest critters, we are increasingly interested in the small, or otherwise forgotten species that exist in New Zealand.

Initiatives like DOC's 'Critter of the week', led by threatened species ambassador Nicola Toki, have gained a following, and put a spotlight on species without the obvious charisma of their feathered neighbours.

Attitudes are starting to change: 'I hear a lot more from the public about the little things they're finding in their area, not just about Kiwi, Kakapo and all the 'k' birds,' Toki says.

The problem is that some of these species are disappearing before us; By the time we notice them, they could be gone.

So here are just 10 of our native species that are on the brink of extinction, or may already be lost: Some are so rare they only live in one patch of grass, or beneath a single rock.

A sketch of the Open Bay Island leech, drawn in 1904 shortly after its discovery.

OPEN BAY ISLAND LEECH: A ONE ROCK WONDER

In the early 20th century, a botanist was looking for weta in a bird's nest on Open Bay Island, off the coast of Haast, and was bitten on the hand. The culprit was a leech species, which was not seen again for some time.

Eighty four years later, a scientist was photographing penguins under a boulder on the island when he was bitten on the eyelid. The leech had re-emerged.

Few species are as elusive as the Open Bay Island Leech, which feeds on the feet of nesting birds, specifically Fiordland penguins. It highlights a interesting conservation issue: Is a predator that feeds on another threatened species just as worthy of protection?

The leech gives a rare perspective on this issue, as it has found itself on both sides of this debate. It is preyed upon by introduced weka, which almost wiped the leech from the face of the earth. The island's weka were culled a few years ago to give the leech and other species on the island a better chance to survive.

Whether there are any leeches left to protect is an open question. The last time a leech was seen was in the 1990s, when the world's entire known population appeared to be living beneath a single rock.

Professor Geoff Baylis with the last surviving Three Kings Kaikomako in the wild in 1945.

The species has already been lost for an 84-year period, however - if it bites the right person, it may be rediscovered once more.

THREE KINGS KAIKOMAKO: LAST OF ITS KIND

It was once considered the world's rarest tree species, for one very good reason: There's only one left in the wild.

The small tree with glossy green leaves is endemic to one of the Three Kings Islands, north of Cape Reinga. They were likely widespread on the island before the introduction of goats, which ravaged the species until only one tree remained, on a steep slope near the peak of the main island.

The tree was discovered in 1945 by Professor Geoff Baylis from the University of Otago. Since then, it has survived droughts, storms and other threats.

Boulders near Kaikoura where the eyelash seaweed has been found.

Because the tree was female, and did not produce seed, it was thought to be the last tree that could exist. But after several decades, researchers managed to get the plant to produce seeds, and the species was cultivated.

It remains critically threatened, however, and has little genetic diversity, because all individuals are descended from a single tree, which still exists today near the highest point on the island, overlooking the Pacific Ocean.

THE EYELASH SEAWEED: ANCIENT AND TINY

The red, stringy seaweed is both the size and shape of an eyelash, and only appears at certain times of the day.

A Teviot flathead galaxias, our rarest native fish. Its global population is confined to an area less than a hectare in Central Otago.

It was discovered in 2005, and has only ever been found in Kaikōura - more specifically, it has only been found on two individual boulders, each on a different part of the coast. It is intertidal, meaning it could only be seen at low tide.

Despite its small, indistinct appearance, the eyelash seaweed is genetically distinct from other seaweeds, meaning its closest relatives likely lived millions of years ago.

It is unclear how the species fared during the 2016 earthquakes. Much of the coastline was uplifted, fundamentally changing the coast's ecosystem, which may mean the species is now extinct.

TEVIOT FLATHEAD GALAXIAS: FOUND IN HEADWATERS OF A FEW OTAGO STREAMS

A Hamilton's frog. Only around 300 are known to exist.

Our native freshwater fish are unusual in our animal kingdom - a loophole in the law means they have no specific legal protection, like many other animals.

While only one native fish species has known to become extinct (the Grayling - ironically, our only fish with specific protection), the Teviot flathead galaxias is the closest to joining it.

The small fish is only found in a few streams near the Teviot river in Central Otago. Its habitat covers an area roughly the size of half a rugby field, most of which is on private land.

The fish are long-lived, and can reach 20 years old; they remain in the streams where they were born, and can withstand both the searing heat and the snowstorms that characterise the climate extremes of Central Otago.

HAMILTON'S FROG: THE SILENT FROG

New Zealand has four species of endemic frog, all of which are notably different from others around the world, with a high degree of evolutionary distinctiveness.

Our frogs are small, don't croak, and don't have a tadpole stage - they grow in small gelatinous sacs and hatch as froglets, effectively miniature frogs.

Hamilton's frog is the largest of our frog species, and the rarest. Almost the entire population lives on what is known as frog peak on Stephens Island in Cook Strait.

The rocky outcrop is the highest point on the predator-free island, and covers an area of roughly 600m².The island had been razed of forest for farming in the early 20th century, but the population just clung to survival on the rock.

Since then, they have become victim to another species - Tuatara. Tuatara have flourished on the island, but predate on Hamilton's Frogs. A Tuatara proof fence was built around frog peak and a small population has been moved to another island for safety.

On that same island, a lighthouse keeper's cat, Tibbles, was famously said to have eaten the last Lyall's wren, a flightless songbird. That story is likely apocryphal, as there were hundreds of feral cats on the island at the time.

BARTLETT'S RĀTĀ AND THE SPIRIT LIVERWORT: AROUND 13 TREES LEFT

Cobble Skink are only found on one stretch of rocks at Granity beach, behind the town's pub.

It was discovered in 1975, in a surviving forest remnant in the Far North. They can grow up to 30m tall and have greyish bark, which flakes off easily and makes them distinct from other rātā species.

Its flowers, much like other rātā, blaze brilliantly in the summer months - unlike its red-flowered relatives, Bartlett's rātā have white flowers. Its wild population is only found in three forest fragments near Spirits Bay, at the very top of the North Island.

At last count, there were only 13 trees left, most on private land. Others have been cultivated and planted elsewhere, but they are effectively clones of a single tree, meaning the species has little genetic diversity.

But if the Bartlett's rātā is rare, it doesn't compare to a plant that only exists on its branches. The spirit liverwort was discovered in 2005, and is one of our 24 native liverwort species.

It appears to only grow on Bartlett's rātā, and thus far, has only been found on a few branches from two of the remaining Bartlett's rātā trees; one of our rarest species plays host to an even rarer one.

Titanomis, a mysterious moth only seen 10 times.

COBBLE SKINK: PUB DWELLERS

It has one of the easiest descriptions for a species' home range you could imagine: 'Behind the Granity pub.'

The cobble skink was discovered in 2007, on a stretch of sand at Granity beach, on the West Coast. The species was likely once spread more widely on West Coast beaches, but is now only known on one small stretch in Granity - literally behind the town's pub.

As of 2017, 40 cobble skinks were known to exist. Granity beach has been steadily eroding, damaging the surrounding houses, which has likely had a serious impact on the skink population, too, washing them out to sea.

Last year, the entire population was captured and relocated to Auckland Zoo.

Only two Tepakiphasma Ngatikuri stick insects have ever been found.

It was fortunate timing - earlier this year, a large storm swept through Granity, and likely would have destroyed the skinks' habitat.

TITANOMIS: THE FROSTED PHOENIX

The giant moth is one of our greatest conservation mysteries. Only 10 have ever been found, the last of which was caught in 1959, trapped in the floodlights at Waipapa Dam in Waikato.

Attempts to categorise the moth have been unsuccessful, as it does not appear to have any close relatives. The 10 confirmed sightings range over 80 years, in all parts of the country. Little is known about the species except that it is attracted to light and is likely a forest dweller, based on the white colourisation of its wings.

The Mokahunui stag beetle, a native species that only exists in a patch of grass the size of a living room.

Moth experts have combed the country since then, searching for a surviving population of Titanomis, but have not found one. There is speculation it may be an overseas species, but because it cannot be identified, it is generally regarded as endemic.

It may be extinct, but there are species that have been rediscovered after a longer period of absence, such as the giant moehau weta.

Due to a shortage of moth experts, there have been efforts to stir public interest in the moth to buoy a rediscovery effort - in 2001, a DOC report recommended giving it the common name 'Frosted Phoenix' to make it more interesting.

TEPAKIPHASMA NGATIKURI: ONLY TWO EVER FOUND

Only two of these stick insects have ever been found, both in Radar Bush at the northernmost tip of the North Island.

Two nymphs were discovered in 2008, and were raised to adulthood so they could be formally described in 2010. Extensive searches in surrounding areas have not unearthed more specimens.

New Zealand has 23 known stick insect species, but Tepakiphasma is notably different from other New Zealand stick insects - it has more teeth on its claspers and its egg has a perforated cone. It was therefore classed in its own genus.

The species was named by Ngāti Kurī, kaitiaki of the area in which it was discovered.

MOKOHINAU STAG BEETLE: SURVIVES IN ONE PATCH OF GRASS ON REMOTE ISLAND

The flightless beetle only exists in one patch of grass on an island known as 'Stack H' in the Hauraki Gulf. It is unknown how many individual beetles remain, but their patch of grass is roughly the size of a living room.

The species was devastated by introduced rats, which made it to every island in the group except for Stack H, where the last beetles remain. It is one of our largest beetle species - males can grow to 3cm long.

The most ever seen at one time is nine. Because its range is so limited, it is extremely vulnerable to extinction. One fire would be enough to wipe out the species forever.