The Brown Tree snake (Boiga irregularis) is an interesting snake that has caught a lot of news headlines over the past decade. It’s a rear fanged colubrid snake endemic to the Northern coast of Australia, Papua New Guinea, and the Islands in northwestern Melanesia. It’s venom is thought to be both neurotoxic and cytotoxic, but because of the small teeth as well as the rear fanged nature of the venom delivery it’s rarely a threat to humans. They are one of roughly 25 species of Boiga commonly known as “cat eyed snakes”. They are highly arboreal spending most of their time in the canopy of the rainforest feeding on birds, lizards, bats and a variety of small rodents. They are an extremely slender snake reaching up to six feet, but more commonly measured at between three and four feet in length.
Now I could go on about the characteristics of the Brown snake for quite a while seeing as I’m a fan of all snakes, but that’s not what’s made this interesting snake such a celebrity over the years. The rise to fame started just shortly after WWII when inadvertently they were introduced to the small military Island of Guam. Many believe that they came in on freighters carrying supplies for the troops, and soon after their population exploded. This was most likely because of the abundance of food sources on the Island, which came mainly in the form of native birds such as the Mariana Fruit Dove, the Guam Flycather, the Rufous Fantial and the Micronesian Mysomela. As a matter of fact biologist believe that the Brown Tree snake may be the cause of up to a dozen native bird species extinction. Snakes probably play important roles as predators in their native ecosystems, when they are introduced to new areas with prey that are not used to them, this normally important role wreaks havoc on native animals. With the abundant food supply and lack of any main predator to slow their population growth down there’s no doubt why this invasive species thrived in it’s new environment. There have been recent studies where there could be up to 100 Brown Snakes per hectare (2.5 acres).
It’s not just the local wildlife that is suffering, but even the electrical grid is being taxed by this invasive species. The arboreal snakes stretch from trees onto the power lines and create an arch that can destroy the power supply lines that provide the much needed electricity to the islands inhabitants. These power outages have caused millions of dollars in repairs to the island over the years. As you can see these invaders are causing a stink in Guam. The bigger question is what to do about them? How do we put the cork back into the bottle?
Enter the Brown Tree snake control, interdiction, research and eradication act. Which sole purpose was to find a scientific way to get rid of this pesky invasive species to the tune of up to $2.6 million dollars per year from 2006 through 2010. The first thing that comes to mind when I hear this is, I know a bunch of fun spirited herpers that we could hire for not much more than a plane ticket and a good supply of beer that would happily catch every Brown Tree snake on the island and we would save the government load of money, but I digress.
One of the ideas was to identify potential predators and introduce them into the habitat. So let’s think about this for a minute. Let’s introduce some invasive species to eradicate an invasive species? Sounds like good science to me? Maybe the story of the Cane toad In Australia comes to mind? Well if you haven’t heard it, it goes something like this. In 1935 there was a major issue in Australia with the cane beetle. Seeing as Sugar cane was a major industry and these beetles would not only eat the crops leaves, but more importantly the larvae would feed on the roots of the plant. They felt that something had to be done to reduce the threat of the cane beetle on their Sugar cane crops. The idea to introduce the Cane toads as a natural predator came from the Bureau of Sugar and Experiment Stations. In August of that year 102 young toads were released in Northern Queensland. The bad news is not only did they not have any effect on the Cane beetles attack on the sugar cane crops, but the introduced Cane toad now number up to 200 million strong and have been the culprit to destroying much of the fragile Australian ecosystem. Not to worry because one the two main candidates to help in Guam was in fact the Cane toad along with the Red-bellied Black snake. Fortunately cooler heads prevailed and they realized that the introduction of said species may “possibly” have a positive impact on the reduction of the population of the Brown snakes, but would most certainly have a negative impact on other species on Guam and thankfully the plan not implemented.
After millions of dollars of research we still seemed to be no closer to the answer to the growing problem of the Brown Tree snake. But fear not there’s always a plan and this one comes from the sky above! No literally I mean the sky above. In 2010 the US Department of Agriculture dropped expired mice that had been injected with Acetaminophen, the generic equivalent for Tylenol, into a small test area that had make shift parachutes on. You see it seems that Acetaminophen is deadly to the Brown snake, killing them within 72 hours, and they felt that putting tiny parachutes on dead mice packed with the drug was the best way to kill off the invaders. I’m not really sure you could make this stuff up, but in fact the test was so successful that they have decided to expand the skydiving Tylenol packed dead rodents to a larger area. They will drop 2000 Brown Tree snake killing rodents into the entire fenced in area that the air force base encompasses to the tune of eight million dollars. I haven’t checked on the cost of tiny parachutes lately, but I’m pretty aware of the cost of frozen rodents and Tylenol and someone seems to be making some extra profit on this event. If the results are positive there are plans to expand this measure to the entire island of Guam, I wonder what that will cost?
For more than 60 years Guam has been dealing with the invasive Brown Tree snake and still to this day there has not been a solid plan to eradicate them from the island. I’m guessing that the hopes are that these latest efforts are the best we can come up with and with the people and economy of Guam on the line I can only hope that it will be effective, but I still can’t help to think that this problem seems to have a much easier fix than what is being proposed. But then again what do I know? I just clean snake poop for a living….