Herps in the News: Brown Tree Snakes in Guam

The rear fanged mildly venomous arboreal brown tree snake has recently been a large topic of discussion in the herp world. This Columbridae is native to Australia and Papa New Guinea and spends its nights being active in the treetops searching for small mammals, lizards and birds to consume. Natural predators are predatory birds, other snakes, and carnivorous mammals that are native to this snake’s natural habitat.

In the mid 1900s, this highly successful snake was able to establish a strong invasive population on the tiny pacific island of Guam. The cause was thought to be the increased port activity during World War II. With no natural predators and an abundance of prey this snake was able to thrive. Since its introduction to the small island nation, countless reports have been blaming this snake for the decimation of the native bird populations.

Plans have been instated to eradicate this snake from the island. First and foremost precautions have been taken to insure there are none of these squamates aboard shipping vessels visiting the island. However these measures prove to have little or no effect on the already established population. There has been discussion of introducing potential predators of this snake to the island, such as the Cane Toad. Conversely such efforts could have more detrimental implications on the native wildlife of the island. Historically similar efforts have proven faulty. An example being the Indian Mongoose introduced to some Caribbean Nations and Hawaii to protect crop fields from an influx of snakes and rats. Unfortunately the mongoose caused more harm to the ecosystems of these habitats than comfort, being the largest contributor to the extinction of 12 native reptile and amphibian species on Puerto Rico. Furthermore, offspring of any introduced predators to Guam could pose as an alternative food source for these opportunistic feeding Brown Tree Snakes.

Just recently CNN, as well as other news conglomerates, have reported on a new plan to suppress the brown tree snake population in Guam. Interestingly the plan is to bomb the island with poisoned mice intended to poison the brown tree snakes. The mice will be lased with a small but snake-lethal dose of Tylenol, and will be scattered throughout the island by aircraft. The Brown Tree Snake is known to consume anything that acts as an easy food source, and it is assumed these snakes will readily accept these dead poisoned mice. In effect the United States will be initiating chemical warfare on these invasive herps and currently controlled test runs are underway on Air force bases in Guam.

I found this to be an interesting account of herps in current events, even though it does not portray them in the greatest light. However I am very interested in anyone’s opinion on this topic. I understand that the extermination of the Brown Tree Snake on Guam theoretically will help restore and benefit the natural ecology of this island, but is it too late to attempt any drastic efforts with out further damaging the Island? Also what do you all think is a potential problem with this latest proposed plan?

Personally I think what is done is done, and anything short of capturing and relocating these snakes will further tarnish Guam’s ecosystems. First of all, I have worked with captive snakes and anyone else who has knows that there is a good percentage of snakes that will only accept live prey. Therefore Guam will still be stuck with a population of reproducing brown tree snakes that will not be eating these chemical weapons (poisoned mice), thus deeming this plan ineffective. Also, what else will be consuming these poisoned mice? And what problems will occur there? I am sure a small dose of Tylenol will have little effect on larger mammals, but the smaller inhabitants of Guam that would love a rat on a plate would probably not fair too well. Furthermore it didn’t take much research for me to realize that the Brown Tree Snakes are not the only contributor to the decline in Guam’s native bird population. Habitat loss from human development further poses threats to these bird populations. It is just clear to me there are a large number of variables that go into this equation. However it will be interesting to keep watch of the efforts made, because they could be beneficial for other efforts like the python influx in the Everglades. Thanks for reading and feel free to post your opinions on the matter.

http://www.cnn.com/2013/02/28/us/guam-snake-drugs