There is an effective trap in use for Brown Tree Snakes. It consists of a mesh cylinder with one way opening flaps on each end. The snake can get in but cannot get out. To entice the snake into the trap there is a live mouse inside. The mouse is in a wire mesh box so that the snake cannot kill the mouse once inside the trap. The mouse must be fed on a weekly basis. This makes trapping very labor intensive. Never the less, this trap is used extensively on Guam around the sea ports and airport and Guams Division of Aquatic and Wildlife Resources is using trapping to clear large areas of jungle (>25 hectares) of snakes. We use these traps on Saipan to hopefully capture snakes that have just entered or to locate a rising snake population.

Numbers and placement

Saipan - 150 in port areas. Presently traps are being focused into one area near seaport and the airport.

Tinian - ~30 at seaport.

Rota - ~ 30 at seaport.

Difficulties in trapping snakes here On Guam traps have proven to be very effective. In the CNMI however, despite all of the effort and numbers, there has never been a snake captured in a trap.

There are probably several reasons for this:

Low snake numbers - There are just not a lot of snakes here, which is good (no complaint about this). On Guam any patch of jungle, no matter how small, has an excellent chance of  harboring snakes.

Abundant prey base - competing chemical and visual cues. The bait mouse in the jungles of Guam is about the only warm blooded animal in the area. For the snakes this stands out like a beacon. In the CNMI there are still plenty of birds, rats, mice and shrews. All of these smells and sights take the snakes attention away from the mouse in the trap.

Low snake movement in relation to the abundant prey base - The snakes do not have to move much to find something to eat. This reduces the likelihood that a snake will come in contaact with a trap during its normal nightly movements. On Guam studies have shown a great deal of snake movement. They are constantly moving through the jungle searching for food. This increases the odds of a snake running into a trap. Snakes on Saipan probably do not move as much.

Maintaining the bait mice are the major limiting factor in medium to large scale trapping programs.