27 May 2020
DISCOVERY OF GLOSSY BLACK COCKATOO CHICKS BRING HOPE FOR BUSHFIRE RAVAGED KANGAROO ISLAND
Q and A: Behind the scenes of the search for hope on Kangaroo Island
Kangaroo Island is considered a hot spot for biodiversity, offering a safe home to iconic Australian species like kangaroos, wallabies and koalas, but also for lesser-known species like the Kangaroo Island dunnart and the glossy black cockatoo. Prior to the devastating blazes, it was estimated the island was home to approximately 370 glossy black cockatoos, found nowhere else in the world. Up to 75% of this population lived within the 210,000 hectare area that was burnt, sparking fears for the future of the species.
With funding from WWF-Australia, thanks to amazing supporter generosity, Natural Resources Kangaroo Island has been surveying damaged habitat and inspecting nests that survived the fires.
Come behind the scenes with Karleah Berris from Natural Resources Kangaroo Island as we find out what it takes to search for signs of hope on Kangaroo Island.
Q. What have you found in the glossy inspection so far? How many nestlings have you seen? Is it more or less than you'd normally see this time of year and where on the Island are you finding the nestlings?
A. We've had a pretty good start to the nesting season this year. So far it's a bit hard to tell if things are different from previous years. What happens is quite often on eastern Kangaroo Island, the glossy black cockatoos there will start nesting around February/March. In the past five years or so we've seen them on the western end of the island where birds tend to nest a little later, starting more in March and April.So far we've seen our regular nesting start on the eastern end of the Island. We had a really good start in February and currently have 23 nestlings in nest boxes, 10 of which we've banded already. That's about on par with what we usually see this time of year. Out west though I think the next few months will be telling whether we actually have as many nestlings because they traditionally do start a bit later. We're just seeing those nests start now.
Q. Are you seeing nestlings in bushfire-affected areas?
A. Yes, but there are a few notable exceptions. The south of Kangaroo Island was hit really badly by the bushfires. We have a large nesting area down there, which the birds haven't returned to so we expect there has been some mortality of that flock. There are another couple of nesting places where the birds haven't shown up to this year. Understandably, they tend to be the areas where we've lost a lot of food habitat. In the areas where there is some food habitat left, they're having a go, which is great. And we're keeping a really close eye on those to see whether they've got enough food going forward to keep those nestlings going until fletching.
Q. How do you check on a nest so high up in the trees?
A. We’ve got a couple of methods for checking nests. We have a tiny little infrared camera that we mount on an 18 metre telescoping extendable pole that we can shuffle all the way up the tree and have a look in the nest. But some nests over 18 metres high require us to get up there physically and climb the trees to look in them.
Q. How did the chicks look? Do they appear healthy?
A. So far this year the chicks appear healthy, particularly our eastern end chicks, which are of the size that we can band them now. We've been able to get a few out of nest boxes and given them a health check and they’re looking in really good condition. We've had one nestling on the Dudley Peninsula so far, which was in really, really good condition. That's our furthest, most eastern nesting site, which has only started to be used in the past five years. It's really exciting that that flock is continuing to expand out there. It's a bit too early to tell the condition of the birds in the fire-affected area because they're a few weeks behind the eastern birds.
Q. And what are the chicks looking like at this point?
A. It's a big range. Just after they hatch out of the nest, for the first couple of weeks they're just a little ball of yellow fluff and then progressively over the next few weeks they start to get those black feathers coming through. Then you'll start to get bits of black all over them. Usually the face is the last area to have black feathers and that will remain quite downy until they're about eight weeks old.
Q. What is life like for these chicks at the moment? What do they eat and how long would they spend on the nest?
A. Life's pretty boring for our glossy nestlings. Once the nestling hatches, the mother might brood at one to two weeks, so she'll stay in there with it during the day. The father's going out and collecting she-oak and feeding that to the mother. The mother then feeds it to the chick. But once that chick's a couple of weeks old and it's still quite small and downy, at that stage the mother will join the father and they'll go out feeding together and just leave the nestling unattended in the nest all day. So if they're close to a lot of she-oak, sometimes the mother might pop back around lunchtime to give it feed. But for a lot of these chicks, they're just sitting in a nest box or a nest all day from about seven in the morning till about four in the afternoon without seeing their parents.
Q. And roughly how long do they spend in the nest on average?
A. The glossy black cockatoo, out of all our cockatoo species in Australia, have the longest nesting period. It's about three months that they're sitting in there before they fledge.
Q. And what is the survival rate for the glossy chicks? What threats do they face at this vulnerable stage in their life?
A. When we monitor the survival rate of glossy chicks we calculate nest success from when eggs are born to when they fledge. And out of that, each egg that's born has about a 35-60% chance of turning into a fledgling at the end of the season. Most of the losses occur at the egg stage and we think that's because some females just aren't incubating their eggs properly. Potentially, they're being disturbed by possums, corellas or galahs, which takes them off the egg a lot, so it gets cold. Plus, some might just have infertile eggs every now and then as well. Once eggs hatch then they've got a pretty good survival rate. It's up around 60 -70% for nestlings, so we don't lose many after they hatch. But the biggest issue we have is possums predating on eggs and nestlings. In fact, we’ve had nestlings that are quite large, up to five weeks old, being taken by possums.
Q. So what do these chicks mean for the future of the species?
A. So every glossy nestling on Kangaroo Island has always been incredibly important. The whole reason we think the population declined over here in the mid 90s was because there wasn't enough recruitment to replace the natural mortality of adults each year. We solved that problem over the past 25 years by increasing their success. But now that we've potentially had a drop in population again, the only way we're going to rebuild the population is to continue to have these young chicks coming through and surviving to fledging. So for the future of the bird, it's really important that as many nestlings as possible survive over these next few years. And it's also really important that we're planting trees and getting good food resources out there for them once they come to breeding age.
Q. How do you combat the threat of possums? And what’s the best method of protecting us against possum predation?
A. We’ve actually got a really simple fix for that. We put corrugated iron around the base of the nest trees and that just stops the possums from climbing up. We do have to get up the trees ourselves and trim the branches so that they can't jump across from other trees. So while a simple fix, it does require us to do it and go and check on those trees annually.
Q. Are there enough nests and is there enough food to support the glossy population at the moment?
A. In the coming weeks donations from WWF-Australia and Koala Furniture will be used to replace artificial nest boxes lost in the fires. About 35% of known nests were destroyed, but food is probably our biggest concern of the two. Initial surveys have found that 54% of the she-oak feeding habit on kangaroo Island was burnt to an extent that it won't be usable until it regenerates.
Q. Are you seeing any other positive signs in your monitoring and survey work?
A. We are seeing some really positive signs in terms of she-oak regeneration. Traditionally, we thought that she-oaks mostly came back from seed released after the fire and that some trees might come back from basal resprouting. We're actually seeing quite a lot of basal resprouting this time, which is good, so those trees that have survived might actually produce seed a lot quicker than we were thinking.
Q. So what other recovery work are you doing at the moment?
A. We're doing a big planting this year of 6,000 she-oaks across approximately 30 properties on the island. We're really trying to spread out our she-oak plantings because, as we've seen in this bushfire season, having everything in one area might not be such a good idea. We're thinking it's good to spread the trees out across the landscape because what we've found is those small isolated patches of she-oak have become really important to the glossies post-fire.We've got landholders involved, most of them will be planting their own trees for us, which is fantastic because of the COVID-19 restrictions we have in place at the moment. We'll be helping those landholders out rather than having a single site with a big volunteer day. We're also putting up new nest boxes. We've got some of our original design nest boxes as well as some tubes that we've sourced from Western Australia that we're putting up in sites where we know we've got enough food to support breeding. We'll be doing that progressively over the next few months.
Q. Are the COVID-19 restrictions affecting your work as a whole? How are you adapting?
A. There’s one big impact that the COVID-19 pandemic has had on us. Winter has traditionally been a time on the island where we've organised a really big planting day with 40 to 50 volunteers showing up per day to plant she-oaks for the glossies. We’re not sure whether that's going to be feasible this year. We've done plenty of small plantings in conjunction with landholders where it's just us and the landholders, so we're not bringing lots of people onto their properties. That has been a bit of an adjustment but I think it's also good from a risk management perspective in terms of spreading our she-oaks out across the landscape. In terms of our normal fieldwork of putting up nests, we have a field team of two, who go out together and do that work. We haven't been doing our usual amount of volunteer work because quite often volunteers come out in the car with us. So we’ve had to do a lot of the work on our own this year, but so far we're still getting everything done, which is good.
Q. So what's next for the project? What work still needs to be done?
A. Heading forward, we've still got a lot of work to do on some of the nests that have females in them, plus the fire has caused the metal collars to drop off from around the base of some trees. We don't like putting those possum protection collars on while females are in the tree because it creates so much disturbance. It does mean that we all have to go out just after the eggs have hatched or we have to go out in the evening while she's out of the nest for 10 minutes and try to quickly tie a nest collar on. That's the big project that's happening at the moment, trying to make sure every nestling is protected, and all those nest boxes. And in future years the big thing is just getting more she-oaks into the landscape. We've seen how easily we can lose so much she-oak so quickly, now what's really important is spreading out lots of the tree across Kangaroo Island.
Natural Resources Kangaroo Island has partnered with Nature Foundation to establish a fund to directly support the Glossy Black Cockatoo Recovery Program, making it easier for members of the public to donate. Help fund the glossy black cockatoo’s recovery here.
You can also help WWF-Australia continue to deploy funds to care for wildlife and restore habitat lost in the fires by donating.
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