• /
    • Archives /
  • 30/11/1999

Archives For 30/11/1999

Ulva Island eradication update: 3 March 2011

Brent Beaven —  08/03/2011

 
The DOC website has the latest updates on the Ulva Island rat eradication.
___________________________________

It has now been two weeks since the public meetings and I’m sure that many of you are wondering what is happening. Unfortunately, we have very little news from the island itself. As mentioned previously, the rat traps have gone past the point of preventing population growth, so we have scaled our trapping checks back to once per fortnight so that staff can focus on the planning to eradicate rats. The last check, just prior to the meeting, brought the total number of rats caught to 70. These have been caught all over the island. The next trap check is scheduled for Friday – I’ll update you as soon as I get the results.

This upcoming rat trap check will be our last. We will close the traps after this so that the 3 days of effort per check can be redirected onto more urgent tasks – such as planning for the eradication. It is important to understand that the rat population has reached a point where its growth will no longer be influenced by any efforts that we put into trapping – even if we were checking traps daily.

Project Manager

Effort has continued toward planning for an eradication operation. The Department will finalise its planned approach by the end of this week and we will then focus our effort onto the required preparation and planning. Regardless of the method chosen, we have appointed a project manager, Paul Jacques, who will be able to work full time on making Ulva Island rat free again. Paul has been the project manager for the possum control work on Stewart Island and we are reallocating his essential possum control tasks to other people and deferring or cancelling non-essential work.

Has this been tried before?

As part of the planning, we have also been reviewing other island eradication operations and discovered that we aren’t the first group to be in this situation after all. Back in 1995, Fregate Island in the Seychelles group (located in the Indian Ocean) was invaded by rats and they attempted to eradicate them while numbers were still low using bait stations. This is a similar situation to Ulva in that rat numbers were building rapidly and had unlimited food supplies. The bait station operation failed and they had to wait until rats reached peak population density and exhausted the food supply before they were able to eradicate them using an aerial bait drop.

Fundraising

Recently we received a real boost to fundraising for the eradication from Birdlife International Community Conservation Fund. This fund donated $5000 to kick-start fund raising. If you wish to help Ulva Island become rat free again, then the Ulva Island Trust will be co-ordinating any donations. Keep an eye on their website (www.ulvaisland.org) for details about how to donate.

Do you have a Question?

In the last few weeks there have been lots of good questions asked about what is going on and why. We will try to capture these questions and answers in a Frequently Asked Questions section loaded on the Ulva page of the DOC website. We should have this in place within the next two weeks.

If you have a question, feel free to give me a call or send me an e-mail.

Brent

In Animal pests, Southland, Ulva Island , , ,
permalink

Kakapo ‘curse’ hits breeding season – but more eggs to come

Sirocco the Spokesbird —  28/02/2011

Skraaark! I’ve just had a skype-apo chat with DOC scientist Ron Moorhouse and he’s told me a few things that are happening down on Codfish Island. It’s good news and bad news – so business as usual in kakapo land!

The good news is that so far we’ve got 18 eggs, and we’re still hoping for more – maybe another couple of nests if we’re lucky. Get booming fellas! Go get ‘em, girls!

Comparison of eggs: hen egg (top)
and kakapo egg (bottom)

The problem though is one that’s haunted us for many years – we find it quite hard to produce healthy eggs. Why? Well, it’s a bit delicate – but when you realise that there are so few of us and that most of us are related in one way or another, you might get the idea. I guess this is the ‘kakapo curse’ – when you get over-friendly with a relative, there’s gonna be trouble.

What this means in real terms is that around half of our eggs don’t make it to chick-time. On the nesting table you’ll see that at the moment several of the eggs are listed as either ‘infertile’ or ‘e.d.e’ – which stands for ‘embryo died early’. This is the curse, and it comes from being such a small population.

Removing eggs from Lisa's nest (2002 season)
Lisa laid three e.d.e. eggs this season

Obviously our DOC friends are doing everything they can to help. It was great news back in the 1970s when we kakapo came out of hiding and they found us on both Stewart Island and in Fiordland. There were only a few Fiordland birds, but they were vital in terms of the genetic diversity they offered – the late, lamented Richard Henry may well yet provide some much needed “new blood” through his surviving offspring, Sinbad, Gulliver and Kuia.

The next problem to overcome is that we don’t want too many more boys. We need girls to keep the numbers going up, but in the past there just weren’t enough of them. But luckily a few years ago the scientists worked out one of our kakapo secrets: if you feed up a kakapo girl, then she’s more likely to have boy chicks – because she knows that if she’s healthy, then the boy will grow up to be a lusty, booming stud muffin who will keep her line going.

But if the mum is a bit skinny, she’ll worry that a boy chick will be a runt…so she produces a girl instead! Once they worked that out a few years ago, they cut back the rations to produce more girls – and it’s worked. It goes about 50:50 now, which has got to be good news for everyone concerned!

Two month old Kakapo chicks from 2009 breeding season

So it’s all a bit complicated, and to be honest I’m glad I’m up here on Maud Island having a good old time with local school kids coming to see me, and the occasional ranger for me to jump on.

Chick-time is coming – maybe in the next couple of weeks. I’ll keep in touch with Ron and my friends down on Codfish and I’ll let you know what’s happening. Skraaaark!

In Native animals, Sirocco the kakapo, Southland
permalink

Kākāpō breeding season could be fruitless

Sirocco the Spokesbird —  01/02/2011

Skraaark! Sometimes it’s tough being a kākāpō. In the last month we’ve lost a couple of our elders, Richard Henry and Whiskas, and now it looks like bad news for the breeding season.

We kākāpō are a simple bunch – feed us up and we’ll get a bit frisky, but take away the food and we just won’t be in the mood. What that means in reality is we rely heavily on there being a good supply of rimu fruit down on Codfish and Anchor Islands, and talking to the DOC rangers down there suggests it’s not going well.

Ripe rimu fruit

Mmm... juicy rimu fruit!

Here’s the deal (they explained it to me simply as maths isn’t a kākāpō’s strong point). Around 11-12% of the rimu fruit on the trees needs to ripen enough for us to eat it. Back in October last year the level was around 21% on Codfish, so it was looking good. But now, it’s gone pear (or rimu) shaped, and it’s down to about 9%. That means there’ll be some nests, but not the 20 we were hoping for. The rangers are now hoping for around five.

On Anchor Island it’s down to 6% on most of the trees. There might be enough on a couple of trees to prompt a couple of nests – but hopes for the first of our kind to be born in Fiordland in decades are fading.

A grand old rimu tree.

A grand old rimu tree

It does make you think – go back to pre-human times in NZ, and we were one of the most common birds here (when I say common, I mean in terms of numbers…we were always pretty superior…). So imagine how much rimu fruit there must have been to keep us going. But now, vast amounts of those trees have gone, mainly because of logging and possums.

So it’s a bit sad, but when it comes to breeding, us kākāpō don’t make it easy. Last year wasn’t good but 2009 was a great one. So we’re doing okay…and who knows, keep those wings crossed for some more kākāpō action this season!

If you want to keep track of which kakapo are mating and who has laid eggs this season check out the nesting table.

Sirocco

PS I’ve been asked how my dear friend Whiskas got his name. Well, when you’re a kākāpō – or a DOC ranger working with us – you’ve got to have a sense of humour. He was called Whiskas because if they’d left him on Stewart Island, he would have been cat food… Skraaark!

In Native plants, Sirocco the kakapo, Southland
permalink

It’s your place, have your say…

Andrew Lonie —  20/01/2011

Managing DOC land… How hard can it be?

Well, it’s certainly easier if people tell us what they think. If you’ve got a treasured family campsite, or favourite fishing spot you’d like kept unspoilt – or if you’ve got a gripe about the way wildlife or one of your special places is being managed, we’d like to hear about it.

4WD trip in Oteake Conservation Park. Photo: C Babirat.

4WD - a popular form of recreation on DOC land

 
In Otago and Southland, DOC is seeking comment on what you value (or don’t value) on conservation land by way of a Google Maps mashup. This is an early-bird chance to have input into DOC’s Conservation Management Strategies (more formal consultation will take place later in the year).
Hoiho and chicks. Photo: C Pullar.

Hoiho - an iconic southern seabird - and chicks

It takes about 20 minutes – you can stick electronic pins with comments on a map, showing what you value in different locations and how you’d like it to be managed. There’s also a short survey to complement this and to tell us a wee bit about you.
Stewart Town, Bannockburn Sluicings, Central Otago. Photo: A Lonie.

Stewart Town, Bannockburn Sluicings - one of my own favourite spots

DOC is looking for feedback in other regions too, by different means –  find out how in the Consultations section of the DOC website. But for the Deep South:

Tell us what you value on conservation land in Otago
Tell us what you value on conservation land in Southland

Have your say by adding comments to the Google map.

The Google map lets you mark and comment on places you value

Once you’ve completed the survey you’ll have the option of later receiving the survey results, and being kept up-to-date with DOC’s conservation management plans. And finally, we’d also love to hear from your family and friends on what’s important to them – please pass it on!
Blue Lake, St Bathans. Photo: R Suisted.

Summer family fun at Blue Lake, St Bathans

In Historic, Native animals, Otago, Recreation, Regions, Southland
permalink

Ulva Island invaded by rats

Brent Beaven —  14/01/2011

Hi Everyone,

I wanted to keep you informed of the events unfolding on Ulva Island at the moment.

Twelve rats have been caught on Ulva Island in the last two weeks.

After four rats were caught on Ulva Island in June/July 2010, DOC staff were hopeful that the incursion to this rat free island had been contained. However, in October a keen eyed member of the public passed on a photo of animal prints he took in a muddy creek on the island. DOC experts confirmed that these were made by a rat.

Ulva Island has a network of traps and poison bait stations that are run year round to kill any rats that may get to the island and extra traps were added to this and the frequency of checks increased. Tracking tunnels were also used to try and detect any rats on other parts of the island.

Between August and December, no further rats were caught or detected. This all changed after Christmas day – a total of 12 rats have since been trapped. Of greatest concern is that one of the rats was a juvenile which indicates there is now a breeding population on the island.

DOC staff have been diverted from other work to check the traps and tunnels on a weekly basis. A DOC team of experts will meet shortly to plan a course of action to remove rats from Ulva Island as rapidly as possible.

Since rats were first removed from Ulva Island, on average one rat a year manages to get to Ulva Island either by swimming or hitch-hiking with boats. To date, we have managed to catch these rats as they arrive, preventing them from breeding. This is the first time a rat has evaded all of our traps, established and bred.

Removing and then keeping rats off the island is a difficult task and there is always a chance that we may not succeed. DOC has an excellent record in this field but as always we will need the help and support of the public to achieve this.

I’ll aim to send regular updates out over the next few weeks.

Brent

26 January update

Unfortunately, the picture isn’t getting any better on Ulva Island. Further trap checks have now brought the total number of rats caught to twenty. On top of this, we have been running ten lines of tracking tunnels (baited with peanut butter and have an ink card in them that records footprints). Five of these lines have recorded rat footprints (34% of tunnels). This confirms that the rats are widespread over Ulva Island.

We are meeting tomorrow to plan the best way to eradicate these rats. Luckily, within New Zealand, we are able to draw on some of the best rat eradication expertise in the world. I will let you know what the recommendation is as soon as I practically can.

The rats that we have caught aren’t going to waste. Tissue samples are being sent away for DNA analysis to confirm that they are all related (and hence only one invasion event) and to work out where they came from. This will be achieved by comparing the DNA of rats on Ulva with sample rats from different locations around Paterson Inlet and Bluff. The rest of the rat will be sent to the vet school at Massey University who will be able to provide information on sex, age and if they have bred or not.

We will continue trapping and running the monitoring tunnels to keep track of the dispersal and population growth of these rats. Hopefully, this will also keep numbers suppressed. The set-up that we have on Ulva will not achieve eradication of the rat population that has established. Something further will be required.

We have had many offers of help and support. These are really appreciated and are being built into the planning of how we might achieve eradication.

Regards
Brent

8 February update

The last few weeks that we have been doing intensive trapping have revealed quite a depressing picture. Over 40 rats have now been caught and most of the tracking lines across the island are tracking rats. In short, the population of rats is widespread and rapidly growing.  The trap set up that is presently on Ulva Island was designed to catch and dispatch individual rats as they invaded the island. The trap set up is no longer going to prevent this rat population from growing rapidly on Ulva Island. They are expected to reach maximum population density (regardless of trapping effort) within the next 12 months, possibly as soon as five months. The impacts on the island at this point will be severe. We plan on continuing to check the traps and tracking tunnels to keep track of rat population growth, but apart from this, the traps are past the point of achieving anything useful.

The best focus of activity now is on actions around eradication options. Last weeks expert meeting (involving members of the Islands Eradication Advisory Group) came out with only two options that had any hope of achieving eradication. Both of these involve getting widespread rat bait onto Ulva Island either by an intensive bait station network or by helicopter spreading. We are currently working through the financial costs and the pros, cons and risks of both options and this is what we will be discussing at the series of meetings on Stewart Island during the week of the 14th Feb. Once we, as a community, agree to the best path forward then we can get stuck into achieving it as rapidly as possible.

So, thanks heaps for your support and I am very sorry to have to send this message. It is really hard to believe that it was only one month ago that the first of these rats started turning up in traps.

Brent

In Animal pests, Southland, Ulva Island
permalink