Lamprey feed by sucking blood from fish they've attached their sucker-like faces to. Photo: T. Lawrence, Great Lakes Fishery Commission.
New Zealand's mountains, forests, rivers, beaches and oceans are home to a colourful abundance of living things - and many of them are downright weird. As Conservation Week 2016 wraps up, science reporter Jamie Morton quizzed ecologists on the strangest creatures out there; this is what they came up with.
1. The flightless, booming, nocturnal parrot that smells like a peach
Kakapo were always going to perch at the top of this list of New Zealand's natural oddities.
Large, flightless and nocturnal, the kakapo is an eccentric parrot that can live for decades, and boasts a weird combination of biological features not shared by any other species.
Not only is it the heaviest parrot in the world - males can weigh more than 2kg - but it can store large amounts of energy as body fat.
It's the only parrot on the planet to have a "lek" mating system, by which males compete for "calling posts", or specially dug bowls in the earth where they call, or boom, each night over summer for a female.
Their deep, low-frequency boom can travel several kilometres and isn't the only strange sound that comes out of the moss-green bird: it also makes a loud, wheezing call (chinging) and a pitched "skraak".
The birds breed every two to four years, can walk several kilometres in one night, and are quite adept at climbing trees.
Possibly as a defence against its ancient predator, the giant eagle, the well-camouflaged kakapo became nocturnal and learned to remain still at times of danger.
That hasn't helped it in the face of an onslaught of modern predators, particularly cats and stoats, while rats have been notorious for claiming its chicks and eggs.
Its population has dwindled to around 125 birds, but conservationists have been trying to bolster its breeding on offshore island strongholds.
It wasn't always this way: they were probably once our third most common bird, and famed explorer Charlie Douglas talked about shaking a tree and having half a dozen fall down like apples.
Department of Conservation threatened species ambassador Nicola Toki singled out their curious, funny, quirky nature, and peach-like smell.
Kakapo are further set apart by being the only parrot to have an inflatable thoracic air sac, not to mention a Twitter account - follow the famous Sirocco at @spokesbird.
2. The spider that loves to fish
Think of New Zealand spiders and you'll likely picture katipo, or Aussie nuisances like white-tailed spiders and the much scarcer redback.
But how many of us know our country is home to a spider that likes to fish?
The sneaky fishing spider Dolomedes dondalei, the largest of the three species of dolomedes native to New Zealand, likes to lurk around shaded fringes of freshwater streams and rivers.
Like other fishing spiders, they can grab fish twice as big as them, before using powerful neurotoxins to kill and digest them.
A bully could have the unfortunate fate of becoming a tasty meal for a Dolomedes dondalei waiting in ambush - "anything that they can overpower or catch near the surface, really," said Canterbury Museum arachnologist Dr Cor Vink.
He thought it intriguing that they were found in closed-in stream areas. Where waterways opened out into rocky riverbeds, you'd instead find their relatives, Dolomedes aquaticus.
"Their camouflage is also kind of neat: they have these serated edges with stripes on them, and a slightly different colouring.
"Also, if you frighten them, they'll trap hair around their bodies and pull themselves under stones, and they look like they're covered in silver when they do it."
If they need to, they can stay submerged in the water for up to 20 minutes, but they have to consume their prey on land because, like all spiders, they effectively turn their food into mush while eating it.
In one final oddity, males tended to guard sub-adult females until they could mate with them: trying to do so with fully developed adult females would probably result in a violent death.
3. The stick insect that can survive being frozen
The hardy Niveaphasma genus of stick insect, currently containing only one species, doesn't mind the cold.
In fact, it can survive in alpine areas at 1000m above sea level - unusual for stick insects - and even freezes during the winter.
The grey or brown stick insect is a proud southerner - it's never been found north of Arthurs Pass - and some populations from mountainous areas further inland can happily cope without males, being parthenogenetic.
Genetic work by Landcare Research scientists found that different populations were restricted to a number of areas in the lower South Island during recent glacial advances.
More fascinating, though, were their experiments that showed the insect could actually survive being completely frozen, and then thawed, just like a bag of peas.
4. Attracting the ladies with a song, dance... and pee
Most Kiwis probably don't even know we have bats, let alone some that use their own urine as seductive cologne.
One of the most peculiar things about Mystacina tuberculata, our New Zealand lesser short-tailed bat, is it crawls along the ground.
It can deftly tuck its wings away so it can walk on its elbows and scuttle across the forest floor, chasing weta and foraging for grubs.
But the bat can still fly, and is thought to be one of our most efficient ecosystem providers by pollinating native flowers like pohutukawa, rewarewa and nikau, sticking its furry head into the flowers and getting pollen all over its face.
In one recent discovery, researchers showed the bats use the complicated "lek breeding" system to try to attract female bats, where the males will find a suitable tree cavity, sing a song, and sometimes pee on themselves to smell good.
They also have a strange symbiotic relationship with a wingless blind bat-fly, which helps them by eating their faeces.
"The adult bat-flies even have a strange relationship with their kids, actually grooming the larvae, with the males looking after them by making a buzz sound to warn others of their young," said Auckland Council biodiversity officer Ben Paris, also known as NZ Batman.
"The bat-flies hitchhike with Mystacina by living among the fur of our bats until they reach a new roost and a new source of bat poo."
5. This critter is lord of the slugs
In the Star Wars films, gravel maggots were ghastly worms on the desert planet Tatooine known to devour the rotting flesh of other creatures.
It seems New Zealand - particularly the coast of Wellington - is also home to gravel maggots, but these ones, in coincidence with the capital's Tolkein credentials, are better known to science as Smeagol climoi.
The tiny mollusk's wider genus, Smeagolidae, inhabit upper intertidal zones on gravel substrate here and in Australia.
Measuring less than 10mm, they have no shell, no sex chromosomes and no jaw - but they do have salivary glands, weakly developed snouts and small teeth.
Discovered in the 1970s, the slug's family earned its Smeagol named because they're found underground, though not too far beneath the surface.
As they are among some of the most endangered marine invertebrates in the country, scientists also consider them - wait for it - precious.
6. The meat-eating heavyweight snail
The meat-eating Powelliphanta snail loves to prey on earthworms, sucking them up like spaghetti.
The largest of this slimy species, found in Kahurangi National Park, are considered the sumo wrestlers of the snail world, and measure about 90mm across and weigh 90g - the equivalent of a female tui.
Named after the Auckland Museum scientist who discovered them, Dr A.W.B. Powell, the snails lay five to 10 large eggs a year, each of them up to 12-14mm long, coloured pearly pink, and hard-shelled.
Six years ago, scientists were surprised to find a rare white-bodied giant Powelliphanta snail in Kahurangi National Park.
Being hermaphrodites they can mate with any other adult.
They're also nocturnal, spending the day buried in leaf mould or under logs and can live an incredibly long 20 years.
Unfortunately, they're also one of the most threatened of New Zealand's invertebrates, and a total of 40 species or subspecies are ranked as being of national conservation concern.
These weird creatures of the forest floor are called living fossils, as they haven't changed much in the 500 million years they've been on the planet.
Also called velvet worms, they're of huge interest to scientists because they're something of a missing link between worms and insects - they're similar to both - but they remain a reclusive and little-understood enigma of evolution and biology.
So unique are they that they have their own phylum, onychophora.
Ranging in length between 2cm and 8cm, they look somewhat like caterpillars and have 15 to 16 pairs of stumpy legs along the length of their body.
It's thought they live for around five years, and females produce between 10 and 20 offspring each year; in most species, they bear their young live.
Although there are around 200 species of peripatus worldwide, there are up to 30 in New Zealand, and only nine species belonging in two genera have been described to date.
The velvety skin of peripatus has permanently open pores, which means that they can easily dry out, so they're mostly found in shady, cool and damp areas.
You might spy them in forested parts of the country, and also in remnant patches, scrub, gardens, pastures and city parks.
They hide deep within rotting logs and under leaves and debris during the day, venturing out at night to prey on other invertebrates, which they catch with jets of sticky fluid.
8. Check your local riverbank for these gruesome little suckers
Never mind great white sharks: lamprey might be the most frightening-looking things in our waters.
At a glance, they look like slender eels, until you see the lamprey's sucker-like mouth - a sight that must have shocked two young eelers who came upon one near a Blenheim river in 2013.
While at sea, where it spends most of its life, it uses its circular sucker to attach itself to other fish, before rasping a hole in their flesh and sucking out its bloody meal like a leech.
It's distinguished from eels by its sucker mouth and seven-gill opening behind the head: male adults also have large pouches just behind their mouths.
Scientists believe they spend up to four years in fresh water, living in burrows in silty river edges, before migrating to sea, by which time they've developed eyes and changed in colour to a bright silvery-blue.
While at sea, the lamprey are parasites on marine life until, after another four or five years, they migrate back up streams to breed and die.
9. New Zealand's ultra-ugly "snot eel"
Any list with lamprey must also include the similarly revolting hagfish.
Found in New Zealand's deepest waters, the grotesque species boasts a set of sharp, protruding teeth and a built-in defence mechanism that fires a volley of mucus-like slime at any predators that come near it.
This slime, shot from a battery of slime glands out of up to 200 pores, effectively chokes fish that try to attack it - hence the species also being known as the "snot eel".
Researchers who managed to capture one and hold one up by the tail were able to calculate that the microfibrous slime it secreted expanded up into to an incredible 20 litres of sticky, gelatinous material when combined with water.
Several years ago, a team of Massey University scientists made many weird new discoveries about the hagfish, including the fact that it's not just an ocean scavenger but also a predator.
They were able to capture the hagfish on video burrowing into sand while chasing red bandfish, knotting its tail for extra leverage as it launched at its prey.
The hagfish is a primitive creature: scientists believe it's been around for 300 million years - that's well past the time of dinosaurs, and 299,800,000 years longer than we evolved from archaic humans into anatomically modern humans during the Middle Paleolithic.
10. Polly want a.... carcass?
This list began with a weird native bird, so it's only fitting to end it with one.
Authors of a 1990s report for the Department of Conservation on the Antipodes Island parakeet described it as "inquisitive and mischievous" - but this might not have been the strangest thing you might say about it.
The Cyanoramphus unicolor is somewhat of a cannibal and, like the kea, sometimes preys upon other birds, entering the burrows of grey-backed storm petrels to kill incubating adults.
They're also known to scavenge flesh from the carcasses of seabirds, although they also feed on leaves, buds, flowers and grasses.
The green-coloured, mostly ground-dwelling bird was named by 19th century English poet and artist Edward Lear, best known for his literary nonsense, like The Owl and the Pussycat, and who happened to one day illustrate it at the London Zoo.
According to New Zealand Birds Online, no one knew where this mysterious bird had come from, and it was another 55 years before it was revealed that Lear's "Platycercus unicolor Uniform Parrakeet" was endemic to the remote and windswept Antipodes Island, 872km southeast of Bluff.
Perhaps fitting the bird's often brutal nature, Antipodes Island is characterised by steep cliffs and rocky waters that have claimed several ships.
Conservationists striving to protect the species and others on the islands recently scored a major win by successfully eradicating one of their biggest threats - mice.