- New Zealand has no native land mammals other than bats.
For around 85 million years, these islands were so remote
that the rest of the world's mammals just never made it here.
All the parts of the ecosystem that mammals would fill
instead went to birds, or lizards, or insects.
A lot of those birds are flightless,
because there was nothing they had to fly away from.
And even the bats spend a lot of time on the ground.
Then in the 13th century, Māori arrived
bringing with them one now-extinct species of dog, and Polynesian rats.
That wasn't great for the local species,
and then in the 18th century,
Europeans arrived and brought... a lot.
Rats, stoats, ferrets, weasels, possums,
all predators which the local creatures had not evolved to defend against.
If New Zealand wants to keep its unique ecosystem
and wants the local species to recover,
at least the species that aren't already extinct,
then the blunt fact is that either the local species
are going to survive, or the predators are.
The only places in the world that have managed
to completely eradicate invasive species
are very small islands a few square kilometers across,
or fenced-off reserves that are regularly patrolled and studied.
And most of those are in and around New Zealand!
But clearing something the size of a country,
and a rural country at that, that's not just a challenge,
that's a moonshot.
So today I met with people from Predator Free Wellington,
because they're some of the folks
who are making a start on it.
- So this is one of our trusty trap boxes.
They get pretty hammered out here, with all the elements.
- There's no one in there right now? Okay.
- Hope not. [both laughing]
No, it's still set. It's still baited.
- Okay.
- And then we've got a bait station there too.
It's basically toxin.
So this is basically a very secure plastic box,
it's locked closed so that pets and children,
that sort of thing, can't get access to the bait inside.
And then in here, we've got a toxic wax block.
- Oh, you're just touching that.
- Yup.
[both laughing]
- Well, people or even cats and dogs
would have to eat a huge quantity of this
for it to have any effects, whereas a rat
only needs really five grams or so for a lethal dose.
- Oh, wow.
- So it makes it a really effective tool. There's also an antidote.
- And that is presumably delicious to rats.
- Yeah, they tend to love it.
I don't know what the flavor is in there,
it's a cereal-based bait, basically.
- Right.
- And then this other one here is kind of interesting.
- We'll wait for the plane.
[plane engine roaring]
Right next to the airport.
- This is called Detex,
so it's a non-toxic type of bait and rats love to eat it,
but the reason we use it is because
it actually glows under UV light, bright green.
And so they'll eat this and then their droppings
or their urine or even their insides will glow.
And so for us and our barrier system, it means that
if we detect a rat along here somewhere,
or we catch one in a trap,
we can work out where it's come from, basically.
- Right. So that peninsula is free of rats.
- Yep. Just about.
- That section isn't.
- Yup.
- And the buffer is, right now, the airport and this bridge here.
- Yeah. So the airport provides a really nice natural buffer area
because rats don't particularly like to be out
in the open where it's super exposed.
And so we don't see much evidence
of them crossing that big concrete expanse.
- So the plan is: start at the edge of the Miramar Peninsula,
eradicate the predators there
and then establish a buffer zone,
and then keep pushing that buffer zone back
and back and back and back
until eventually there are no predators left
in the whole of Wellington.
- We've got about 5,800 traps in our network
and then about 6,800 bait stations of varying types.
- The trap to me just looks like a box with a hole in it.
- Exactly.
- And, if the rat can get in, how does the rat not get out?
- It's basically an entrance on one side
and the mesh at the other side they can see through,
so it looks like a clear run for them.
Which we've found makes them more likely to
go inside and investigate.
And then we've got some lure inside as well.
So there's a paste that just smells really good
and so they'll go in for a nosey.
I can whip this open, there we go.
- Oh, okay. Yeah.
- So it's a pretty grunty trap.
- Yeah. In my head, up until this moment,
I was like, oh, it's a trap.
The rat goes in, the rat gets trapped, you release the rat...
No, you don't. - Yeah, no.
- No. That... - No. This is definitely a lethal trap.
- Yeah. - Yeah.
And it's humane certified to the New Zealand standards.
So we basically want traps that the animal's not
going to suffer more than it needs to.
It's going to be pretty instant, pretty powerful.
I can give you a demo of setting it off if you'd like.
- Yeah, absolutely.
I mean, it's kind of really brutal calculus, isn't it?
Either the rat dies or the unique species here dies.
- Unfortunately. Yeah.
I mean, it's never nice to have to kill animals
and rats, I've got a lot of respect for them,
they're great creatures in their own right,
but unfortunately they just can't coexist with our native species.
So, I can give this a demo.
- On that note. Yeah, let's...
- So I'm just going to use my gloves
'cos they're nice and soft, and lob them in
and hopefully that will set it off.
Two, one. [trap clanks]
There we go.
- Okay. Yeah.
- So it's pretty punchy.
- That's going to be messy.
- Yeah. - Yeah.
How often do you have to clean one of these out?
- Not very much these days, thankfully.
- Yeah.
- Along here it's still reasonably rare but we do catch
probably about three rats each time we service this barrier system.
On the peninsula,
we're catching a lot less rats now, which is nice.
Yeah. Especially in this hot weather.
- You really do have to be so careful.
- Oh, yeah.
- How many people do you have working on this?
- So we've got a full-time field staff of about 25,
and then there's a few of us in the office as well,
doing the data crunching and that sort of thing.
- That's way more than I thought.
- And then on top of that, we've got a huge volunteer force.
So they make up about 10% of the efforts on Miramar Peninsula.
- Right. And it's government funded, presumably?
- Yeah, a lot of it is. So it's a big collaboration, this one.
So, what we can see here, we've had a rat,
come along and chewed this monitoring card of ours.
- So we call these chew cards.
They're a really effective monitoring tool.
It's basically just a piece of corflute plastic
and then we mash peanut butter into the gaps.
- But it works a treat.
So it's been here, within the last week we know,
because we've serviced this quite recently.
- You can't poison the peanut butter then?
- Unfortunately not.
We considered the avenue, but I don't think the...
- Of course,
because that's something that other creatures...
- Other creatures could get to.
A dog could have a nibble.
And it's also the combining of toxin with food
is one of those things that...
- Oh. - ...I don't think you're technically allowed to do.
So, we've got to be very careful to keep it all safe
and legal and all of that.
- No, the trap has not been set off now.
- The trap's not been set.
So it's had a nibble, it's getting interested,
but it hasn't gone in yet.
- Yet. [both laughing]
- The trouble is, as long as there's a breeding pair of rats
anywhere outside that buffer zone, there's a threat.
Alberta in Canada is the only place
outside of the poles where there are no rats,
and that's because rats never got established there.
A combination of harsh geography on all sides
and a vicious, almost obsessive government-backed control program
kept rats out, and still does to this day.
That's what Wellington will always have to deal with,
unless they just keep pushing.
The reserve here, this is where the rats have been eliminated
rather than suppressed, right?
- Yeah, exactly.
So it took us about six months of really intense efforts,
but we've now eliminated all of the rats out of this area.
- So how do you know?
- We've got a lot of monitoring that goes into it,
trail cameras, a big one.
They're just about the golden standard we can get
for monitoring rats.
You can see there's one just tucked down in here.
- Oh, spot the city boy. [both laughing]
Oh, okay. Yep.
- So they're camouflaged to blend in
as best they can, so that the rats don't notice them
and it's pointed at a motor lure.
It's basically got a syringe of mayonnaise inside
with a little motor. - Sure, okay.
- And once a day, it basically pushes out 1ml of
mayonnaise from this syringe.
Without us having to come here every single day,
it's keeping a fresh food source and a fresh lure for these rats.
- And anything that comes to eat it...
- Gets caught on camera.
- Right.
- Yeah. It's a really effective way of basically
telling us if there's any rats left in an area.
And rats seem to love egg mayonnaise,
so it works pretty well.
- And are there any left?
- Not in here.
It's been a huge effort, but now we can safely say it's rat free.
- Is it working?
Well, it seems to. The statistics say
that animal life is recovering on the peninsula.
The key thing is, this isn't limited to just Wellington,
across the whole of New Zealand there are groups doing the same.
There's a government plan called Predator Free 2050,
but it is optimistic. The plan that even admits
that to pull this off on a national scale
they'll need some new scientific discovery to make this easier.
And "new scientific discoveries" and "ecosystem management"
are words that historically haven't gone well together.
Do you think it's going to work?
Do you think that they'll get New Zealand clear by 2050?
- I think they will, yeah.
I think just looking at the progress we've made
in the last couple of years already, particularly here,
we've learnt so much in the last 12 months
that if you extrapolate that out,
I think we've definitely got a good shot of it.
I think we'll crack it.
- Can it be done?
Maybe. With enough money, time and human effort.
And from my limited time here
I'd say that protection of the land and ecosystem,
the Māori word roughly translated is 'kaitiakitanga',
it seems to be part of New Zealand's national identity,
in a way I don't think I've seen in any other country I've been to.
Towns, regions, sure. But never a country.
If anyone can pull this off, it's going to be New Zealand.