Island exterminators

November 27, 2011 9:02 PM

Islands make up only about 3% of the earth's land area but host about 20% of all species and 50 to 60% of endangered species. The biggest threat to islands are invasive species, mainly rats, but also pigs and cats, who feed on nesting birds and native plants. New Zealand has been the innovator in clearing islands of rats because of its endangered populations of flightless birds which are vulnerable. One species of flightless parrot, known as the kakapo, has only 131 individuals left in the "wild" - they are closely guarded 24x7 on Codfish Island, their nests surrounded by rat traps and cameras vigilantly on the lookout for invaders.

The idea of clearing islands of rats was until very recently thought impossible. Rats quickly learned not to touch cyanide-laced food when they saw comrades writhing in death. A new poison called 1080 was developed that caused a slow death with no seeming connection to the food eaten. The rats would take the bait. Starting in 1988 a few intrepid individuals in New Zealand tried to clear a single small island of rats (Breaksea), much to the dismay of officials who thought it a waste of time and money. But it worked. Increasingly larger islands were attempted and new techniques developed using GPS pin-point helicopter drops of the bait. Entire species could be brought back from the brink of extinction by a few people in a few weeks of time. The largest islands cleared to date include Campbell Island (map) in New Zealand, the Galapagos Islands (map) and Rat Island (map) in the Bering Sea. Nearby Kiska Island (sight of a Japanese base during WWII which is still clearly visible on the map) is the next and biggest target, as is South Georgia Island. Over 800 islands have been cleared around the world, but it's still a small amount compared to what could be done. This is a new and evolving technique, Island Conservation is one of the biggest island-exterminators going.

Most info for this post from the great book Rat Island: Predators in Paradise and the World's Greatest Wildlife Rescue (NPR).

posted by stbalbach (39 comments total)

I didn't mention the "controversy" that surrounds this, there are people who disagree with killing rats and cats and goats. There are organized groups around the US who feed populations of feral cats and actively try to stop the killing of invasive species. They have not done well in court as the law supports saving endangered species.
posted by stbalbach at 9:16 PM on November 27, 2011 [2 favorites]

Fascinating post; thanks. I am especially fascinated by rats and islands since I grew up on island which not only had no rats but whose soil was often taken by people to keep rats away.
posted by lesbiassparrow at 9:38 PM on November 27, 2011 [1 favorite]

See Douglas Adams' book Last Chance to See for a beautifully-written section on the Kakapo. Even better, the follow-up TV series with Steven Fry had this fantastic video.
posted by w0mbat at 9:43 PM on November 27, 2011 [3 favorites]

People worked so hard to clear the islands of rats, but every year, the population of Kakapo got smaller. They managed to achieve the impossible - they succeeded in creating a predator-free island. But the kakapo population continued to fall.
Some had put ten years of their life into saving this species, and yet every year they worked, there were still fewer alive than the year before. Even when they started relocating the birds to the islands, there was no sign that the birds would even breed. They didn't breed. They just continued to die.

They had just been dying for the entire history of human settlement. By the time people started trying to save them, the entirely population was mere hundreds.

And with all the effort spent to save them, the population fell to about fifty.
And everyone was working knowing it could all be in vain. Working for years on just... hope.

After all those years of guesswork and hope and fear, one morning (1999 I think) the kakapo population ever so slightly ticked up. For the first time in history... the number got bigger. I can't imagine what that felt like to the people who had worked so hard never knowing if it was all in vain. It was national news. For me it was one of those "you'll always remember where you were when you found out" things. Not really because the birds are important, but because the effort to save them was so heroic, such a leap into the unknown.

The kakapo might still perish, but these island sanctuary techniques developed in the fight to save kakapos will save other endangered animals, including those not cute enough to attract mass support.

Epic win for humanity. The people who pulled this off are heroes.
posted by -harlequin- at 9:58 PM on November 27, 2011 [21 favorites]

Island Conservation (link correction)
posted by stbalbach at 10:05 PM on November 27, 2011

Sidenote on the first sentence: what's the distinction between an island and a continent? I mean, if you choose to look at it that way, the Americas could be said to be one massive island.
posted by kafziel at 10:32 PM on November 27, 2011

Sidenote on the first sentence: what's the distinction between an island and a continent?

Oh, that's easy - islands are land masses that are smaller than continents. A continent is anything bigger than an island.
posted by FatherDagon at 10:37 PM on November 27, 2011 [9 favorites]

kafziel, it's similar to the distinction between a boat and a ship. A boat will fit on a ship, a ship will not fit on a boat. (Continents are arbitrary anyway, they're just a convention we use to organize the world.)
posted by borkencode at 10:45 PM on November 27, 2011

An island is small enough that speciation remains mostly linear, kafziel, meaning that your species evolves towards sustainability instead of aggressive expansion. In large areas, there are speciation events driven by geography that separate species, but later one subspecies wipes out the other, resulting in a more expansionist species overall.

Australian wildlife is commonly endangered by the hyper aggressive species imported from Europe and Asia, especially the human adapted ones, like rats. I'd assume this occurs because Australia isn't quite as large as it looks once you subtract all the desert, not because marsupials are less flexible than placentals.

There weren't afaik nearly such severe problems with importing species into North America, probably because North America is much bigger, mostly habitable, and connects with South America, although serious problems still occurred, ala kudzu.
posted by jeffburdges at 10:48 PM on November 27, 2011 [2 favorites]

We just need to find a cyanide compound that kills rats but doesn't kill these birds. Then we feed it to the birds. The rats learn that if they eat these birds, they die.

Problem solved!
posted by wayland at 11:06 PM on November 27, 2011

See Douglas Adams' book Last Chance to See for a beautifully-written section on the Kakapo.

I did. In 1996, when I was heading towards my final year of high-school and trying to figure out what to do with my life.

Now I have a PhD in ecology and environmental science.
posted by Jimbob at 11:34 PM on November 27, 2011 [8 favorites]

I'd assume this occurs because Australia isn't quite as large as it looks once you subtract all the desert, not because marsupials are less flexible than placentals.

Also, Australia has been lacking, over the last 100,000 years or so, large carnivores.
posted by Jimbob at 11:51 PM on November 27, 2011 [4 favorites]

not because marsupials are less flexible than placentals

Fucken placentals come over here, right, completely uninvited, right, and act like they own the fucken place. They're always jabberin' away in their placental language and talkin' about placentas. Well I say it's about time we had a national debate on placental immigration, and if they wanna come over here they should integrate with OUR society and keep their young in a fucken POUCH like normal fauna.
posted by the quidnunc kid at 2:52 AM on November 28, 2011 [8 favorites]

jeffburdges: "There weren't afaik nearly such severe problems with importing species into North America, probably because North America is much bigger, mostly habitable, and connects with South America, although serious problems still occurred, ala kudzu."

The most problematic imports in NA do seem to be either plant species, or insects and diseases of plants (ignoring humans, or human issues like smallpox). Kudzu is bad, but so is Melaleuca, multiflora rose, privet, tree-of-heaven, eucalyptus, salt-cedar, & cetera. Chestnut blight virtually wiped out a dominant forest species on this continent, now there is sudden oak death, emerald ash borer, Asian longhorned beetle, hemlock woolly adelgid, beech bark disease, and so on. And on.

Oh, yeah, and earthworms.
posted by Red Loop at 3:34 AM on November 28, 2011 [1 favorite]

Shagged by a rare parrot.

http://www.youtube.com/watch?v=9T1vfsHYiKY
posted by By The Grace of God at 4:32 AM on November 28, 2011 [1 favorite]

TC Boyle - king of the moral dilemma novel - nails these issues in his most recent book. Seems to me that invasive species are a natural process, ecosystems require them in order to persist, and resistance to these natural processes on our part is often futile. Hysteria about invasives is simply a societal sublimation of our fear of the other. Think 'immigration controls for foreign ecosystem workers'.
posted by aeshnid at 4:46 AM on November 28, 2011

Oh, yeah, and earthworms.


Yeah, the dense pine forests of northern New England were once immense maple forests. Pine forests are pretty close to deserts by comparison... they only grow where other trees have failed due to poor soil.
posted by Slap*Happy at 5:35 AM on November 28, 2011

By far the worst invasive species is man.

Easter Island can be seen as a microcosm of earth itself.
posted by kinnakeet at 6:11 AM on November 28, 2011 [1 favorite]

The David Attenborough series "The Life Of Birds" did a segment about the kakapo that was absolutely heartbreaking. I can't seem to find it online specifically, but it looks like there are plenty of opportunities to see the series online. It is in the first episode, I believe.
posted by briank at 6:47 AM on November 28, 2011

Seems to me that invasive species are a natural process, ecosystems require them in order to persist, and resistance to these natural processes on our part is often futile.

We have... accelerated this process.

Hysteria about invasives is simply a societal sublimation of our fear of the other.

That, or it's genuine concern for the maintenance of the planet's biodiversity. It's definitely one of those two things.
posted by IjonTichy at 7:20 AM on November 28, 2011 [5 favorites]

Wow. I knew earthworms were an invasive, but I never thought they'd be considered a damaging invasive species.
posted by ocschwar at 7:26 AM on November 28, 2011

There is a completely self-interested reason for preventing invasive species from taking route or eliminating them when possible : virtually all our medications were discovered by examining other species.

We should also convince countries like Brazil to stop cutting down rain forrest too though, maybe in exchange for helping them develop a biotech industry (lobby).
posted by jeffburdges at 7:33 AM on November 28, 2011

resistance to these natural processes on our part is often futile

Clearing islands of rats demonstrably works.

invasive species are a natural process

Humans clearing islands of invasives is equally a natural process, just as humans spreading invasives around the world is a natural process.
posted by stbalbach at 7:45 AM on November 28, 2011 [3 favorites]

Abstruse Goose
posted by jeffburdges at 8:44 AM on November 28, 2011

Also worth mentioning the Karori Wildlife Sanctuary in this connection: an attempt (so far remarkably successful) to create an "island" of predator-free bush on the mainland of NZ. On the edge of a major city (the capital, Wellington) they simply fenced in a section of bush with a fence that is designed to keep out possums, rats, mice and all the other introduced predators that New Zealand's native birds are so defenseless against. It is extraordinary the impact it has had on the birdlife of the city, having this one relatively small breeding sanctuary.
posted by yoink at 9:45 AM on November 28, 2011

yoink, I read about that in Rat Island, 12 square miles fenced off is pretty impressive.
posted by stbalbach at 9:58 AM on November 28, 2011

Also, Australia has been lacking, over the last 100,000 years or so, large carnivores.

Unless you count humans (40,000 years, and an arrival coinciding with the extinction of most then-native Australian megaafauna), or thylacines.
posted by rodgerd at 10:10 AM on November 28, 2011

In reply to IjonTichy and stbalbach - while I would agree that over the short term, we can halt / control the movement of invasives into vulnerable ecosystems, this becomes active management. Such ecosystems are maintained under nonequilibrium states, and do not develop in a healthy fashion. Arguably, they are no longer natural ecosystems, at least as defined by those most closely focused on interventionist solutions.

Concern for the planet's biodiversity requires a more enlightened view of nature as a dynamic process, where local, or even global extinctions of species are viewed with sadness, but in the same way as the death of a close family member.
posted by aeshnid at 11:34 AM on November 28, 2011

Concern for the planet's biodiversity requires a more enlightened view of nature as a dynamic process, where local, or even global extinctions of species are viewed with sadness, but in the same way as the death of a close family member.

I think most of us regard the death of a close family member as something we should put a reasonable amount of work into preventing.

I think you're right that there can be an hysterically OTT side to the "OMG, that plant's not a native, KILL IT WITH FIRE!!" camp--but you seem to be staking out an equally extreme position on the other side. There are such things as invasive and detrimental aliens and it can at times be worthwhile working to slow, halt or eradicate their progress.
posted by yoink at 11:39 AM on November 28, 2011

yoink, my point is that species are no more immune from DNR flagging than my relatives.
posted by aeshnid at 11:55 AM on November 28, 2011

Just a question: If the birds die out naturally, either by predators or by lack of breeding etc, then isn't this nature's way of eliminating a species not fit for survival?

If pandas don't have sex in the wild, then what should humanity's responsibility be to nature if nature makes it so?
posted by amazingstill at 12:13 PM on November 28, 2011

aeshnid, the natural equilibrium includes humans. That is the enlightened view. Humans are not outside or above nature, humans are an integral part of it. The entire world has been shaped by humans for millions of years. We choose to protect Bald Eagles, but shoot wolves. We create our own environment. That's what being human is about.
posted by stbalbach at 12:18 PM on November 28, 2011

stbalbach - I think you misunderstood my point: I agree 100% that we are an integral part of nature. Indeed, we have an unprecedented influence on other species through our actions. However, managing ecosystems by micro-managing individual species is an aesthetic decision, with ongoing cost and uncertain outcomes. Enlightenment flows from an understanding that small victories may only prolong the struggle for existence of species which have run out of niche, and distract us from focusing on the larger-scale objective of sustaining healthy ecosystems. Money spent in one place is necessarily denied elsewhere. Conservation resources are finite and declining...
posted by aeshnid at 12:33 PM on November 28, 2011 [1 favorite]

Enlightenment flows from an understanding that small victories may only prolong the struggle for existence of species which have run out of niche,

The passive voice here is somewhat telling. These species have not "run out of niche"; we have taken it from them, and in some cases it lies within our power to return it to them. Doing so, if possible, clearly helps maintain biodiversity.

over the short term, we can halt / control the movement of invasives into vulnerable ecosystems, this becomes active management. Such ecosystems are maintained under nonequilibrium states, and do not develop in a healthy fashion. Arguably, they are no longer natural ecosystems, at least as defined by those most closely focused on interventionist solutions.

Not sure what you're getting at here. The introduction of invasives is a modern problem, caused by the fact that humans have constructed transportation networks spanning the globe. Trying to minimize the environmental impact of those networks is not the same thing as maintaining an ecosystem in a nonequilibrium state.

Can any ecosystem be truly called a "natural" ecosystem these days, that is, an ecosystem outside the reach of humanity's influence? Either we go out of our way to conserve biodiversity, or we let the systems we put in place destroy it. In either case, we can't help but play an active role in the fate of essentially any ecosystem.
posted by IjonTichy at 12:52 PM on November 28, 2011 [2 favorites]

Another land-based predator free "island" project - Maungatautiri.
posted by Catch at 2:03 PM on November 28, 2011

I agree that the conservationists are heroes, but it does seem hard to shake the feeling that it's like cheering against natural selection, that is, trying to stop the tide of inevitability. But living next to the aforementioned Karori Wildlife Sanctuary, I appreciate the work of environmentalists every time a kaka lands on a tree outside my window.

Keep up the good work - news of continued challenges in this area is frequent news in this part of the world.
posted by Metro Gnome at 2:32 PM on November 28, 2011

This is a good example of the Permaculture concept of edge. Islands have lots of edge where water meets land, leading to more biodiversity as species evolve to take advantage of both land and water habitats, as well as intermediary habitats (beaches, reefs). Edges can be quite fragile, unfortunately.
posted by gray17 at 2:52 PM on November 28, 2011

managing ecosystems by micro-managing individual species is an aesthetic decision, with ongoing cost and uncertain outcomes

That's an opinion not borne out be the facts presented in this FPP.

Money spent in one place is necessarily denied elsewhere. Conservation resources are finite and declining...

One could say that about *anything*, it's a logical fallacy. Money is by nature a limited resource and anytime it's spent results in it not being spent elsewhere. So? The question is, was the money well spent? In fact some very important people have said this is the most efficient conservation program they have ever seen. Entire ecosystems can be restored in a single day with one man and a shotgun. I'm sorry you think island ecosystems are not worth saving, but most people would disagree.
posted by stbalbach at 5:32 PM on November 28, 2011

If pandas don't have sex in the wild, then what should humanity's responsibility be to nature if nature makes it so?

Not to derail from what I'd consider good news about eliminating invasive rats, but I've wondered this about pandas myself. As I understand it, pandas have the digestive systems of carnivores but they eat only bamboo, so they don't have the energy to move around or mate as often as other bear species. I can't help but wonder whether pandas were destined to become one of the millions of species that went extinct on their own.
posted by FreelanceBureaucrat at 6:59 PM on November 28, 2011