Humans did the brown tree snake a big favor. Sometime in the 1940s, they were given a free ride to Guam, probably in military cargo.
There were no predators of snakes on Guam, and no native snakes on Guam except a tiny, blind, insect-eating creature, so harmless that everyone thought it was some kind of worm.
So the native wildlife had no idea what a snake was and that it might want to eat them. The brown tree snake had a free buffet of innocent, defenseless, wildlife. They proceeded to wipe out most of the delicious bird species, cute fruit bats,and colorful little lizards.
You'd think the brown tree snake would at least appreciate all that humans have done for it... but no.
Among other problems, they're constantly causing blackouts, as the US Geolological Survey explains:
Power lines, wooden poles, and guy wires are no greater challenge for these snakes than a tree or exterior wall of a building. Snakes often cause problems by climbing guy wires leading to power poles supporting transformers, distribution lines, and high-voltage transmission lines. When the snakes simultaneously touch live and grounded conductors, they create faults, short circuits, and electrical damages. This results in frequent losses of power to parts of Guam and even island-wide blackouts. Such power failures, brownouts, and electrical surges, occurring on average approximately one every three days, damage electrical appliances and interrupt all activities dependent on electrical power, including commerce, banking, air transportation, and medical services. Power outages caused by snakes have been a serious problem on Guam since 1978, and the incidence of snake-caused outages continues to cause significant problems. Records show that more than 1,600 snake-caused outages occurred from 1978-1997.
Attempts to control this problem include turning off one utility line identified as a major source of snake-caused faults. Since 1985, this line has been shut down from dusk to dawn, the hours when the snakes are most active.
The USGS quotes an estimate of $4 million per year for research and control of the brown tree snake - including searching outgoing aircraft for stowaways that might invade other islands - and that's not counting damages and losses from blackouts or wildlife and environmental problems.
And, adding insult to injury, now they're expecting humans to provide MORE food:
Having nearly depleted the bird populations on Guam, larger snakes have been found scavenging garbage and even sneaking in to steal a hamburger off the barbeque!
Read more at the wonderful USGS brown tree snake website. And in case you ever have a chance to get back at them, don't miss the recipes (scroll down here).