Poisoned Mice Bombing Hopes to Halt Guam Snake Advance (Via Herp Digest)

Poisoned Mice Bombing Hopes to Halt Guam Snake Advance
September 20, 2010 ABC Radio Australia
http://www.radioaustralia.net.au/pacbeat/stories/201009/s3016098.htm
On above URL you will be able to listen to story. The following is the full transcript of the story.

Authorities in Guam are taking their battle against its infestation of brown tree snakes to the skies with the US Department of Agriculture dropping dead mice packed with poisonous chemicals onto forests to provide deadly snacks for the snakes.

It also supplements current trapping systems designed to prevent the snakes from hitching a ride on boats and aircraft to other Pacific islands. 

The species have already wiped out the island's entire native population of forest birds since being accidentally introduced to Guam over half a century ago. They also generate millions of dollars in damage after getting entangled in electric wires causing power shortages. 

Authorities hope the poison laced mice would help put an end to an ecological and economic nightmare.

Presenter: Geraldine Coutts
Speaker: Dan Vice, assistant state director of the US Department of Agriculture's Wildlife Services in the Pacific

VICE: We've been working for years in a large cooperative effort to try to prevent the snake from spreading around the region and at the same time try to mitigate the impact of the snake on Guam and we have done that with a variety of very labour intensive tools, trapping and capturing and the use of detector dogs and such. In the last five years, we have received the official go ahead from the US Environmental Protection Agency to use an oral toxicant, a pseudomenaphin which is a common compound used for pain and fever reduction as a poison for brown tree snakes and we are working on developing the technology to actually deliver this toxic aerially so we can start doing snake control across larger more difficult to access blocks of terrain where snake populations are quite large on Guam.


COUTTS: Including in this particular part of the program now, dead mice laced with this drug or this poison and chucking them out of planes?


VICE: Right, it is a little more scientific approach to that, but yes we use a dead juvenile mice that we then insert 80 milligrams of pseudomenaphin into the body and then attach the mouse to a flotation system, so that when it's distributed out of a helicopter it will float relatively slowly to the ground and actually hang up in the forest canopy. What we want to do is keep the bait from hitting the ground, actually keep them in the tree so that the snake which lives in the trees will be virtually the only thing that can get to that bait.


COUTTS: And how far into the program are you, can you know how successful it is yet?


VICE: Well, we know the bait is very effective at killing snakes. Eighty milligrams is 100 per cent lethal to every size of brown tree snakes that eats it. We know that we can deliver the bait and get it to hang up the forest and we actually do some novel work with this where we're putting radio transmitters in some of the baits. When we drop them, we can go out and find them in the forest and then we can track them and we can determine what actually happens to them. And during this most recent pilot project we started, we put I think ten radios on the ground and we had snakes consume a number of those baits. So we know we can put bait out into the forest. We know the snakes will consume it, we know the snakes will die when they eat it, so we definitely have a useful tool here.


COUTTS: So the tracking is to know their habits. So you know how to get rid of them more easily?


VICE: Well really, the tracking is so that we know what the fate of the baits are. We want to make certain that when we're putting those baits out into the forest, that they are doing what we expect them to do and that's get consumed by and ultimately kill a brown tree snake and so we can actually document that snake has eaten the bait and we can got out and recover the snake after it has eaten it.


COUTTS: And how successful have you targeted the canopies of the trees, because presumably you don't want to hit the ground to wipe out other insects and animals that you're not targeting?


VICE: Right, there is a couple of reasons to put it into canopy. One if for non-target concerns, but number two, is to just make it more accessible to the snakes. If it hits the ground and falls in a crack on the ground in rocks or something like that, then the snakes just don't find it. So by putting these flotation systems together, we are able to get about 90 per cent of the baits to hang up in the forest canopy which is really important for us.


COUTTS: How do you maintain your supply of mice? You say they are juvenile mice. Are you breeding them specifically for this program?


VICE: Right, there are actually companies around the world that are in the business of raising mice for using them for like zoos, endangered species, propagation projects and stuff, animals that require food. People raise mice and they sell them as food for captive animals and we're using those companies to help supply us. Ultimately, we would like to be able find something other than mouse though, because they don't last very long in the field, about three days and they begin to degrade and they are no longer useful for the snakes. We'd like to find something inanimate that we could use that would be more persist in the environment and still get snakes to eat it. Unfortunately, we've had a lot of research that has gone into it and there's just nothing that seems to anywhere approach the effectiveness of the mouse.


COUTTS: And do you know how many mice have been parachuted out of the helicopters now as part of this program?


VICE: Just this first pilot project we did about 250 baits or so. It was a very small scale test of our system. We're anticipating moving this project forward in the coming years and so we were out testing our navigation system and testing the bait delivery and all of the things that we need to do to make sure that the system works before we go on a larger scale.


COUTTS: Okay, and is this a program that you are doing by yourselves and getting help from elsewhere?

VICE: The project is actually funded by the US Department of Defence Technological Certification Program. We're doing the work in collaboration with a number of different partners, including our National Wildlife Research Centre out of Fort Collins, Colorado and the local military commands on Guam are providing logistic support and access to property to actually do the project, so it would not be successful without the help of all of those partners.