The kākāpō season of stress and salvation: How scientists and supporters teamed up to take on killer disease
Wednesday, 15 April 2020
The vet had bitter news.
'She sounds like she's choking to death,' the Auckland Zoo manager of vet services James Chatterton told his radio audience last June.
She was a kākāpō chick, Nora 1A, suffering cruelly from aspergillosis, a fungal infection that assails the longs and air sacs of a bird's body.
They operated to remove airway abscesses but she was just too weak, so became the seventh death from the Whenua Hou (Codfish Island) sanctuary off Stewart Island.
**READ MORE:
* Kākāpō population reaches record high of 213, despite mystery illness
* Kākāpō disease 'crisis' which garnered $200k in donations remains a mystery
* First successful artificial insemination of kākāpō in a decade**
Seven deaths sounds bad, but let's get a sense of scale. By that stage 35 kākāpō had been helicoptered to receive intensive care, chiefly at Auckland Zoo and also Massey Wildbase, Dunedin Wildlife Hospital and Wellington Zoo.
That was one fifth of the total population of the island where the kākāpō is making its stand against extinction.
By September it would be 51 evacuees. Nearly a quarter.
A last chance to see
The UK paper The Guardian, reporting on the aspergillosis battle, described the kākāpō like this: 'Deeply weird. Flightless, nocturnal, with fragrant feathers and a comic waddling run…'
Fair enough on all counts, though the fragrance is more musty than you might assume, once nicely described as like the inside of an old violin case.
The worldwide appeal of these birds cannot solely be attributed to their rarity and size, nor even the worldwide comedic appeal of the footage of Sirocco landing atop zoologist Mark Carwardine and getting carnal with his cranium, to the joyous hooting of onlooking presenter Stephen Fry for the TV series Last Chance to See (the very title of which underscores how imperilled the population is).
There's something almost mammalian about kākāpō. Their feathers are especially strokable, their large eyes perhaps more soulful than the average avian, and there's no denying their behaviours suggest wilful character.
The Hitchhiker's Guide to the Galaxy author Douglas Adams found them intriguing, fat birds whose wings were really only good for waggling a bit, though flying is out of the question.
'Sadly, however, it seems that not only has the kākāpō forgotten how to fly, but it has forgotten that it has forgotten how to fly.
'Apparently a seriously worried kākāpō will sometimes run up a tree and jump out of it, whereupon it flies like a brick and lands in a graceless heap on the ground.'
Far more seriously, they struggle to breed. There's a real lack of genetic diversity.
Females can get attached to one partner, carrying the same genes into 20 or 30 offspring, which is why it had come as particularly good news last July that the first successful artificial insemination in a decade, courtesy of Sinbad, a male with a rare Fiordland gene, had rendered chicks.
The sole other success, in the 2008/9 season, had been a world first.
Famously, though, the natural breeding season ties in with the berry fruit 'mast' in the bush, which happens on a cycle of three years or more.
And the 2019 season had been spectacular. Rimu berries all over the place. The population had risen to its highest in 70 years. It was an exhausting time for the recovery team on the island, but a thrilling one.
Then wham. They were dealing with aspergillosis. Very rare in wild bird populations. Hard to detect early, and brutal in its consequences.
'It felt like a real kick in the guts,' recalls DOC kākāpō operations manager Deidre Vercoe. 'Things had been looking so promising, but changed so quickly.'
Her darkest fears were dark indeed - this had the potential to kill so many birds, unravelling decades of conservation effort.
The team had done risk analysis work but aspergillosis was considered very low risk. Only one case had ever arisen, in 2012.
'To suddenly have an outbreak of that scale was a shock. The level of breeding we had that year in itself was new to us - so we were dealing with the biggest ever breeding season and the biggest ever disease event at the same time.
With veterinarians across the country, the team worked to develop a plan, adapting it as they learned more.
The extent of scientific collaboration grew to something amazing. Veterinarians, scientists, virologists and researchers stepped into important roles via Auckland and Wellington zoos, Massey's Wildbase and Dunedin Wildlife Hospital - and DOC rangers from throughout the country joined in.
The logistics of flying 50 kākāpō off an offshore island up the length of the country were, Vercoe says, not easy. And all the birds remaining in the wild on Whenua Hou were checked and had blood samples taken - itself a 'monumental' undertaking.
But then not much about the crisis effort was, given the intensity of the care that the birds needed - batteries of CT scans, nebulisers, medications feeding, blood tests, some surgery.
On top of which the research needed to face what was effectively a new disease in kākāpō, and try to understand it in a very short space of time
Scanning the whole population wasn't possible, so they had to prioritise individuals based on their history.
This, says DOC kākāpō science advisor Dr Andrew Digby, involved quick data analysis, running models in search of clear contributing factors and analysing blood test results to see if this could help predict aspergillosis.
The questions were urgent: Was it due to an unusual set of environmental circumstances, or ana unusually virulent strain perhaps introduced via their management, or an undetected pathogen that made some kākāpō more susceptible.
From around the world came offers of support from a range of experts in man field, mostly via Twitter. They formed a collaboration of international geneticists, microbiologists, virologists and veterinarians from New Zealand, the UK, the USA, Canada and the Netherlands.
'Most of these people don't work in conservation or even with animals - many are medical researchers. They've all dropped current work to tackle this problem, donating time and money to do so.'
Digby finds this unity of purpose hugely encouraging, with potential benefits for other studies too, a deeper knowledge of the genetics of the aspergillus fungus involved in this outbreak could help further global understanding of aspergillosis in humans - a serious and growing health problem.
'It's really demonstrated the positive power of social media to me too - it's a hugely underrated tool for scientists'
Vercoe agrees. Social media interest was huge from the DOC perspective as well.
'We took a very open approach with our communications, making sure we were keeping people as informed as possible, through the good news and the bad.'
The number one question was reliably the same: how can we help. From established programme supporters Meridian and Air New Zealand to a specific donation option that raised $200,000 from countries far and wide.
Gradually the good news was coming back from the exhausted labs.
'I think it was the 17th bird tested who was our first negative. That was a relief - I'd been extremely worried as the positives kept coming back.
Next raft of good news, the affected birds were responding unexpectedly well to treatment.
'It took months of treatment, but birds we thought would surely die were improving.'
Ultimately, when the last of the evacuees, Margaret Maree, headed home in early February, the crisis had been weathered.
The season that started with147 birds end with 211. Still a small number but on balance, a big step ahead for kākāpō recovery.
And now, of course, we have Covid-19 and a lockdown of the humans. For the recovery team, the timing has been reasonably fortunate. They'd been winding down monitoring of the breeding season and those birds who had recovered from aspergillosis - all doing reasonably well.
'Outside a breeding season, we're very hands-off with the birds. They're essentially wild birds taking care of themselves. Our rangers are safely at home.'
Not to draw too long a bow, but can Vercoe see any lessons applicable to the Covid-19 emergency?
'It can be amazing to see how people really pull together in a crisis. It takes everyone working together to get through, and a clear path of action.
'In our crisis there were times when we didn't fully understand what the best path to take was, but decisions had to be made based on the best information to hand at the time. We couldn't just sit and wait to see what would happen, there was too much to lose… being prepared to adapt quickly as new information came to light was really important.
'When people feel committed to fighting for something and can clearly see the role they have in that fight - that purpose and connection brings out such strength.'
Kākāpō recovery numbers:
21 birds were affected
9 birds died - 2 adults and 7 chicks
48 birds - 17 adults and 31 chicks were sent to the mainland for assessment for aspergillosis, 43 from Whenua Hou (Codfish Island) and 5 from Pukenui (Anchor Island)]
All 55 birds that remained on Whenua Hou (55) and all the breeding females on Pukenui (21) were health checked and had blood samples taken.
Longest hospital stay was Toiora at 277 days. She underwent 8 CT scans, 28 sedations/anaesthesias and had over 150 diagnostic tests done
Longest stay for an adult bird was 261 days for Margaret-Maree.
100 CT scans were conducted on birds with the number of scans per bird ranging from 1 up to 8 (Toiora).
It is likely that without treatment all 21 affected birds would have died. It is also conceivable that the numbers of birds infected was reduced due to the decision at the end of May to remove all remaining chicks and females from nests to minimise exposure.