Extinction rebellion
Why we can be inspired by kākāpōs’ escape from their own deadly disease
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 ka¯ ka¯ po¯ chick, Nora 1A, suffering cruelly from aspergillosis, a fungal infection that assails the lungs 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.
Seven deaths sounds bad, but let’s get a sense of scale. By that stage 35 ka¯ ka¯ po¯ 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 ka¯ ka¯ po¯ is making its stand against extinction.
By September it would be 51 evacuees. Nearly a quarter.
The UK paper The Guardian, reporting on the aspergillosis battle, described the ka¯ ka¯ po¯ 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 ka¯ ka¯ po¯ . 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 ka¯ ka¯ po¯ forgotten how to fly, but it has forgotten that it has forgotten how to fly. Apparently a seriously worried ka¯ ka¯ po¯ 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 2008/09 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 ka¯ ka¯ po¯ 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 ka¯ ka¯ po¯ 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 ka¯ ka¯ po¯ , 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 ka¯ ka¯ po¯ 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 an unusually virulent strain perhaps introduced via their management, or an undetected pathogen that made some ka¯ ka¯ po¯ more susceptible?
From around the world came offers of support from a range of experts, 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 says.
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.’’
‘‘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.’’ Deidre Vercoe
DOC ka¯ka¯po¯ operations manager