A really bittersweet year
Thursday, 29 August 2019
The best kākāpō breeding season on record has had a grim coda, with an outbreak of aspergillosis on Whenua Hou/Codfish Island killing a number of adult birds and chicks and endangering many more. As Naomi Arnold reports, veterinarians and veterinary nurses from around the country have rallied to help, a response that’s typical of the profession’s approach when it comes to kākāpō and other endangered wildlife.
It’s all hands on deck to help kākāpō this winter as an outbreak of aspergillosis on Whenua Hou/Codfish Island curbs the best breeding season on record. As VetScript went to print, the respiratory fungal disease has killed seven birds (two adult females and five chicks), with 13 still affected by aspergillosis. Another 31 have been ‘cleared’; 22 have been returned to Whenua Hou/Codfish and 22 remain on the mainland (of whom 19 are in hospital). As of early July, no new cases have been identified. Fighting the disease has required a combined effort from veterinarians and conservation staff at the Department of Conservation (DOC), Auckland Zoo, Wellington Zoo, Massey University’s Wildbase Hospital, and Dunedin’s Wildlife Hospital.
In April spirits were high: a whopping 252 eggs had been laid in the earliest and longest breeding season yet. More than 100 of these were fertile, and 86 live chicks hatched. It was huge news, especially given there are only 142 adult kākāpō left alive – and in 1995, there were just 51 birds on the planet. But recently things took a turn for the worse when rangers discovered that some of the chicks on Whenua Hou/ Codfish, a stronghold of DOC’s Kākāpō Recovery programme, had the fungal infection aspergillosis.
“It’s been a really bittersweet year,” Auckland Zoo Veterinary Services Manager James Chatterton says.
The zoo regularly helps DOC with native wildlife efforts in breeding, monitoring, healthcare and hand-rearing, including kākāpō. But the aspergillosis effort required a big jump in resources as the birds were progressively taken from their offshore island homes to the mainland and checked for signs of the illness, first the chicks, then adult females, then males. The zoo put out a call for veterinarians, veterinary nurses and bird keepers to help with the outbreak, and nearly 100 people responded. “None of us could do this in isolation,”
James says. “I guess if there [has been] some good to come of this in the short term, it’s been about what a wonderful country, region and world we live in. We’ve had offers of help not only from down the road and in Australia but also from Europe, the US, Canada, Singapore – all over the place people are offering to help with different skills. It’s amazing how in conservation, people drop everything to help. It makes me feel good to work in a sector where everyone pitches in if they can.”
Because aspergillosis is hard to diagnose definitively, they have followed a process involving looking for granulomas on CT scans, then using endoscopy to check the birds’ airways and culturing samples to confirm the disease. In a way, kākāpō are lucky because the birds are monitored so closely, and early signs of aspergillosis were noticed. When the new chicks hatched they were growing well until a couple of them died. Then a couple more plateaued with their weight gain, which alerted rangers that something was wrong. The intervention was immediate and thorough.
“The only way to have success is [to] diagnose early and treat with everything you’ve got,” James says.
As care efforts continue, he says one of the main problems is figuring out why this happened. Only one kākāpō has ever died of aspergillosis before now. One thought is that a very warm year on Whenua Hou/Codfish encouraged the late bloom of the common fungus aspergillus in nests or the forest floor, another is that there is a yet-to-be identified pathogen that compromised the birds’ immunity.
DOC Director-General Lou Sanson says that despite the tragedy, this breeding year is still one of DOC’s biggest-ever successes. But much of its work could not be done without the veterinarians whom DOC employs and those from the wider sector who help at times like these.
“I have nothing but praise for what our veterinarians do for our precious wildlife,” he says. “The hatching of the new chicks is a huge step up and we have to celebrate it. We use veterinary services around the country for our birds, and they are quite incredible. When the chips are down, having those veterinarians come in and knowing that they’re doing everything they can is great. DOC knows very little about many of these diseases, and it’s a huge learning curve for us every time we get something like this. I want to acknowledge the huge amount of resources Auckland Zoo and everyone else has put into the programme.”
This cooperation is a natural part of the job. DOC Wildlife Health Coordinator Kate McInnes, who is President of the NZVA’s Wildlife Society special interest branch, says that because conservation is an area where you don’t make much money, it creates a ‘can-do’, collaborative culture among those caring for New Zealand’s wild creatures.
“There have been many practice veterinarians come to work on the [kākāpō] islands, too. Volunteers come and help out, sometimes to help feed them during the breeding season and to watch nests. But as soon as veterinarians are on the island they get asked a whole lot of questions and they end up providing a lot of veterinary advice. Like, “Hey, do you think this disinfectant is really cleaning these bowls properly?”, and “Can we get you to have a quick look at this funny eye?” Everyone mucks in and helps, and there is a lot of job satisfaction for everyone involved. There is a real connection that people get with kākāpō that inspires more and more of this work.”
One recent success in this type of national collaboration was the world’s first bird brain surgery at Massey’s Wildbase Hospital to correct a meningoencephalocoele, a deformity in a kākāpō chick’s skull where its fontanelle was still open, allowing its brain and dura to herniate out. Veterinarians from Wildbase, Auckland Zoo, Wellington Zoo and the Wildlife Hospital conferred to determine that surgery was the best way forward, and after Air New Zealand flew the bird for free to Wildbase, a team of veterinarians led by Wildbase Director Professor Brett Gartrell and veterinary technicians at Massey carried out the pioneering surgery. Following initial recovery, the chick was rehomed to the Wildlife Hospital where he could recover with other kākāpō chicks.
DOC Kākāpō Recovery Group Scientific Advisor, conservation biologist Andrew Digby, says the department has been using veterinarians more and more in the recovery programme, especially as the scale of the breeding seasons has increased. Having animal medicine expertise on the ground on kākāpō islands such as Whenua Hou/Codfish, Anchor Island, and Little Barrier Island/ Te Hauturu-o-Toi has meant the rangers are upskilling too.
“We try to manage the kākāpō in situ as much as possible rather than sending them to hospitals. Having veterinarians on the ground means we can treat [the birds] quicker and pass on that training. We try to have a veterinarian on each island at all times during breeding season, providing that support for sick chicks and for diagnosing other problems and doing necropsies.”
Kākāpō are different in every respect from other birds, Andrew says, and that applies to the veterinary medicine side of things as well. There is currently a study underway with Auckland Zoo investigating why kākāpō have very low blood values of vitamin D, while eating a very vitamin-D-rich diet from rimu fruit.
Meanwhile, the situation continues to change daily at Auckland Zoo. James says it has been tough caring for the personable birds while knowing their airways are full of granulomas. Although difficult to diagnose until very close to death, aspergillosis is usually fatal once the granulomas have formed.
“Chicks in groups are playing with each other, and the awful thing is if you look at the CT scans you can see how terribly sick they are – but then you look in the pen and they are walking around, climbing over each other and eating berries and look fine. It can be heartbreaking.
“We always say that from the birds’ point of view they don’t know what the future holds; all they know is they’re here in the veterinary hospital and not running around in the forest. We try not to let ourselves be weighed down with knowledge of the future. We try to make every day as least impactful on them as possible – lots of fresh browse, try to keep them nice and calm, keep our interactions as short and friendly as possible and provide new things to investigate every night. We try to keep
them as happy as possible while they are in hospital.”