This Is How It Ends: As old as the Southern Alps, kea are on the edge of extinction

Thursday, 14 October 2021

Kea evolved in isolation over millions of years, and now holidaymakers are feeding them to death. Andrea Vance and Iain McGregor report for Stuff’s This is How it Ends series.

A long, piercing beep prescribes the kea’s fate.

For three minutes, a portable analysing machine has been measuring lead levels in the bird’s blood.

As we wait, the young female stomps, bashes and bites at the cage holding her.

Beeeeeeeeeeeeep, the machine spits out the results to ecologist Laura Young. The lead levels are too high for it to read.

“[It] says high, which means that it's over 65 micrograms per decilitre. So, this one's definitely got lead poisoning in quite a bad way.”

Young sighs. “That's a shame. Not many come back with ‘off the chart’.

“It's quite an ominous sign for the first one of the day.”

Since daylight, Young has been searching Arthur’s Pass village for the inquisitive mountain parrots. They are attracted to populated areas by the lure of human food.

They swoop down from forested slopes with a flash of their vivid orange underwing, and an eerie screech. Māori named them for their long cry.

Of the three Young captured, all have acute lead poisoning, likely from chewing on roofing materials.

The stultified creatures will be transported to the South Island Wildlife Hospital, in either Christchurch or Dunedin, for treatment.

But the clinic was full and three more birds, trapped in the village the following day, had to be released.

“We've recaptured one who has previously been in the wildlife hospital, who we released into the wild and who then found his way back to the village,” Young says.

“Unfortunately, there's no space left in the wildlife hospital. So, we're going to have to put these ones back and hope they are right for a while longer.

“The chances are high that these guys will have lead poisoning. It does make you pretty sad.

“But it's an ambulance at the bottom of a cliff approach. What we need to be doing is not feeding kea and removing lead from the buildings where they hang out.”

Young bands, measures and weighs the birds, and gives them a general health check. She also takes feather samples for further research.

A kea sightings database and other citizen science tools help experts understand what is happening to the population.

“There's a consensus that kea are declining, particularly east of the Main Divide. People would suggest a noticeable decline, probably in the last 10 or 20 years.

“It's hard to get a population estimate when it's such a highly mobile species. The most recent one is somewhere between 3000 and 7000.”

Kea are as old as the Southern Alps themselves.

Over the centuries, they have adapted and evolved, absorbing ecological and geographical change.

But their greatest threat was the arrival of humans, and within a few years we may wipe out their existence altogether.

They belong to this land, originally from Strigopidae, a parrot superfamily that diverged from other parrots around the same time Zealandia was peeling away from Gondwana.

Dinosaurs, and ice ages came and went. The thrusting of tectonic plates formed the Southern Alps and the geological changes inspired another split. The “proto-kākā” evolved into the Norfolk and Chatham kākā (both now extinct), the kākā and the kea. The kākāpō is a relative.

Fossil records show the kea once populated the North Island, but the last ice age saw the subspecies divided again, this time by the Cook Strait.

The arrival of humans drove kea from lowland beech forests into the mountains. Although Māori hunted the bird for feathers and food, European settlers decimated the populations, with burn-offs and the introduction of sheep, deer and goats, which grazed on the shrubs and berries they needed for food.

Driven by hunger, the kea began to attack sheep (although mainly vegetarian, they will scavenge carrion). They pecked wounds and feasted on high-calorie fat, leaving the livestock vulnerable to fatal infection.

Angry farmers demanded a cull, and a 10 shilling bounty was placed on their beaks. The extermination programme lasted for 100 years, slaughtering an estimated 150,000 kea.

Today, the kea is more likely to be shot by a tourist with a camera. But the risks are just as great.

“Curiosity certainly kills the kea in lots of different ways,” Young says. Their inquisitiveness draws the bird to tourist villages, like Arthur’s Pass, Aoraki /Mt Cook, Franz Josef, and Fox Glacier.

They both delight and frustrate humans with destructive antics, stripping wiper blades and window seals or snapping off antennae with knife-sharp beaks.

It’s a behaviour and intelligence that evolved to help them survive in the harsh alpine winters: they’ll eat whatever presents.

Visitors, and some locals, use food to lure them in for that perfect Insta pic, which only encourages them to return.

Because this food source means they don’t need to forage, the juveniles have more time to get into trouble.

“They like to hop on to roofs and pick the lead head nails, flashings and car wheel weights. Even up in the mountains, they eat carcasses shot by hunters with lead ammo, and get a big hit of lead,” Young says.

The substance is sweet, and soft, so the rascally young birds love to chew, bite and lick it from old buildings. It gets into the blood system and over time is deposited in their organs and bones.

“Kea can get pretty sick with lead toxicosis, just like humans can. You don't always see obvious symptoms. Other times they’re vomiting, stumbling around and being quite thirsty, going over to puddles and trying to drink lots of water from the road. Doing strange behaviours.

“The effects of lead poisoning probably makes them more susceptible to being hit by cars and having slow response times.”

At least six Arthur’s Pass kea die each year from ingesting lead, and those are just the ones found by researchers. Around 95 per cent of the young birds tested in Arthur’s Pass village have toxic levels.

Kea can also react badly to human food. One death was recorded on the West Coast from chocolate poisoning.

And like all of New Zealand’s native birds, they are at risk from predators, and occasionally investigate rather than flee.

A report by former Parliamentary Commissioner for the Environment Jan Wright estimated almost 80 per cent of native birds are either threatened with, or at risk of, extinction.

There are 23 species at risk of immediate extinction, including the orange-fronted parakeet (kākāriki), Chatham Island black robin, New Zealand fairy tern and the white heron.

Since the arrival of humans 700 years ago, we’ve wiped out close to 50 species, among them huia, the South Island kokako, moa, and Haast eagle/pouākai.

“Overall, our forest birds have declined dramatically, certainly since humans arrived in New Zealand,” says Colin O'Donnell, Principal Science Advisor with the Department of Conservation's Terrestrial Ecosystems and Species Unit.

“Most forest birds are threatened these days, in some ways. We have no real concept of just how busy our forests used to be: there would have been zillions of different birds zipping around all over the place.”

Habitat loss is a “blatant” cause of decline, he says.

“We've cleared three quarters of the forest of New Zealand and the birds that rely on forests, don't have them anymore. They've disappeared from places that are now prime agricultural country.

“The Canterbury plains …used to be all native habitats for these birds… so not insignificant chunks.

“There was a corridor of bush from Christchurch, joining the Banks Peninsula with the Alps. Banks Peninsula was entirely covered in forests and there were … kiwi, takahē kākāpō spread across the plains and linking up with the foothills.”

Introduced predators like mice, rats, hedgehogs and stoats are ruthless exterminators of forest birds, killing an estimated 25 million each year. But browsing animals have also changed forests dramatically.

“Deer and possums cause the structure and the quality of the habitat to decline and that will influence things like food supplies and nest places,” O’Donnell says.

“There are other threats as well. The common and German wasps… eat nectar sources that the birds require, and sometimes sting native species. It can cause death.

“Avian malaria is a parasitic disease that came from Europe. That causes death when they're under stress.

“It is a hard job for a lot of these birds all these threats, just finding food, a safe place to breed.”

Birds in our southern-most forests are facing a new onslaught in the next year: a beech mast in which most trees flower and produce seed.

Up to 250kg of seeds can fall in an area the size of a rugby field, a feast for native birds, but also rats and mice, which multiply in numbers.

That drives a plague of stoats, which feed on the rodents, and native birds.

In the last decade, DoC has become adept at predicting mast event years, using climate modelling. Beech trees produce seeds when a summer is warmer than the preceding summer, they then flower and seed in the next summer.

Using these forecasts they plan predator control operations, including aerial 1080 drops.

“When we lose forest birds, we lose some pretty important things that go on in the forest,” O’Donnell says. “Flowers require birds, insects and lizards to pollinate them and reproduce. Birds do a really good job of dispersing fruits and seeds.

“If you want to keep healthy forests, birds have a role to play. There is a food web that should be in balance.”

Melanie Mark Shadbolt is kaiwhakahaere (Chief Executive) of Te Tira Whakāmataki, which works to provide mātauranga (knowledge) Māori solutions for biodiversity loss.

“We're losing our identity,” she says. “You know, if we lost the kiwi, we are no longer Kiwis, are we?

“Our language itself evolved from the sounds of the birds. If you were to go back and listen to the original te reo Māori it would sound very much like birds talking.

“So if we lose our language, the animals that helped give us our stories, we lose all of that. We lose our culture. The way we operate as Māori is embedded in connections to nature.

“And for indigenous people, in particular, their livelihoods and their culture is going to be lost for our modern, Western society. I think we have downplayed that component.”

At the wildlife hospital vet Pauline Howard rehabilitates kea by injecting their pectoral muscles twice daily with edetate calcium disodium, or EDTA. It binds to the metal ions and the birds are given extra fluids to allow the lead to be excreted in the urine.

The chelation treatment can take weeks, and the staff work hard to keep the birds occupied. Howard, a volunteer like all the hospital’s staff, loves to watch the birds leave.

“We are not animal hoarders,” she says. “You can see that after a few weeks they really want to go.

“Sometimes [there is] quite bad, stereotypical behaviour. You can tell they're quite stressed, they'll start bouncing up and down. That means you need to do something to their environment to enrich it, make some toys, or change their cage around so that they're not quite as stressed.”

The kea are released in remote valleys, at a distance from villages. But, all too often the juveniles return.

“Ideally, they would dislike the experience so much here [at the hospital], that they didn't want to be near people,” Howard says. “But unfortunately, juveniles like being fed.

“There's no doubt that when you get kea near people it’s not good for their health. They pick up lead, they get hit by cars. They eat inappropriate food.”

Young has a simple solution: “don’t feed kea, ever.”

“Never leave your food in kea habitat because even if you're not actively feeding them, they're so clever they'll come and take your stuff anyway,” she adds. “The more we interact with them, they become more and more curious, more investigative, and more susceptible to getting into trouble.

“Be careful when driving through places like Arthur's Pass village, Mount Cook, ski field car parks, where they're going to be standing in the road. Especially the young ones: they're just learning how to fly and don't have quick response times.

“People can do a lot to protect kea.”