Sunday, March 22, 2009

Guam Snake Dogs

A USDA inspector leads a Jack Russell terrier
through a snake search of a B-52 Stratofortress.

A repost from August 24, 2004 of this blog

Brown tree snakes are native to eastern Indonesia, the northern part of Australia, Papua New Guinea, and the Solomon Islands and probably arrived on the U.S.-owned island of Guam as stowaways in cargo from Papua New Guinea in the late 1940's or early 1950's.

The snakes multiplied rapidly on Guam, where they had no natural predators, and they have decimated the once-vibrant native bird population on that island. Ten of the 13 native forest birds of Guam are now extinct due to the brown tree snake, and the three species that still exist are barely hanging on. Several species of lizard have also been wiped out, and bat populations are now being predated on as well.

Guam's brown tree snake population is now estimated at about 40 per acre of tree habitat, or more than 26,000 snakes per square mile.

There are several different methods used to prevent the spread of brown tree snakes. Trapping and nighttime spotlight searches reduce the number of snakes in areas where cargo is packed or stored. The goal here is not to eliminate brown trees snakes (a hopeless task using current methods), but to exclude them from docks and airports in order to prevent them from being transported by airplane or boat to another island (such as Hawaii) where they might wipe out even more birds and small animals.

Experience has shown that specially trained Jack Russell Terriers are the best method of finding snakes in cargo-loading areas before they manage to make it on to airplanes. The U.S. Department of Agriculture's Wildlife Services (APHIS) branch currently employs 14 terriers on Guam to detect the brown tree snake. These are rescue dogs that originate from either California or Texas. Wildlife Services pays for the dogs to be shipped to the island.

When the terriers arrive in Guam, they are trained by a US Dept. of Agriculture-certified trainer. Training takes about 4 months, depending on the dog and the handler. Once a terrier is trained, the dog is used to inspect outgoing cargo, and transport vessels, such as aircraft or service ships. The brown tree snake is not poisonous, so there is no danger to the dog. >> For more information



Anonymous said...

The brown tree snake most certainly is venomous! Like other venomous colubirds, it has fangs in the rear of its mouth, so it isn't particularly efficient at delivering venom (it has to gnaw on you for a bit), nor does it posses especially potent venom in the first place.

PBurns said...


A Brown Tree snake is generally classified as non-venomous, as the small amount of very weak venom that it does have does no damage to humans and is almost always entirely asymptomatic. There have been no human deaths from these snakes as far as I know, and they are all over Guam and bite people every day. In short, almost ANYTHING is more dangerous to the children of Guam than a Brown Tree snake -- a chair, their mother, a piece of string, food, water, and even clothing. Note that Brown Tree snakes are NOT related in any way to the King Brown snake of Australia, which is a truely venomous snake.

All snakes will bite, of course, and the Brown Tree snake is pretty aggressive. If a baby is bitten, you might worry about infection and give the child an antibiotic to avoid any chance of sepsis, but I would not worry too much about venom. Of course, someone somwhere will always have a profound allergy to something, so that cannot be ruled out. There are millions of snakes on Guam, however (and none on Hawaii) and people thre are bitten everyday and no deaths have been reported. That tells you quite a lot. Bumble bees should be so lucky to have that kind of record -- mothers, chairs and pieces of string as well.

One of the reasons dogs are used to locate Brown Tree snakes on Guam is that if a dog is bitten, it comes to no harm whatsoever -- same as humans. Baby birds, of course, are another matter.

Dogs are not used (at least intentionally) to locate truely venomous snakes like cobras, boomslangs, rattlesnakes, and mambas because every encounter would have a very high chance of being a last encounter.

Of course all snakes get a bad rap, venomous and non-venomous alike. Australia, just over the water from Guam, is suppossed to be a seething mass of poisonous reptiles, if you believe Steve Irwin, but in fact most Australian venomous snakes can kill nothing larger than a mouse, and more people are killed every year by horses in Australia than by snakes. That bit of news is left out of the Animal Planet series, of course, because it does not make for great TV. Steve did a lot of good for snakes and lizards, so he is forgiven for this small omission.


Tarako said...

Im sorry to disappoint, but there are NOT millions of snakes on Guam!! That would mean that any resident on the island would see at least 5 or more snakes on a daily basis. I promise you, its not true. one million looks like this: 1,000,000

PBurns said...

Tarako, just because you don't see snakes does not meet they are not there. I take pictures of raccoon and fox in my yard every night, and my neighbor has never seen one once!

And, for the record, the population of snake on Guam IS somewhere betwen one and two million. See >>


Eva said...

Brown tree snakes are nocturnal so humans don't see them that much unless they keep animals that make good prey, like chickens, which will attract the snakes. Plus the snakes mostly live in the jungle and humans don't venture there so often, and when they do, it's during the day. Very hard to negotiate all those vines, spiderwebs (full of BIG spiders), and whatnot during the day, not to mention at night!

seeker said...

We have lots more JRTs in Texas that would love a job killing snakes of any kind. I think they need more about 30 or 50 to really clean things up and protect the children. For some reason: movies, commercials, etc. we are blessed with an abundance of the little stinkers, both JRTs and Rat Terriers, who need an important job and where they are well taken care of. And of course, they can work as long as some people at 15 to 20 years. LOL!

Turn em loose and stand back.

Debi and the TX JRTs

Unknown said...

I'm a breeder and I'm so proud of my Jack Russell's. They have brought several dead snakes in to show off their Jill.