When the U.S. Military Came to Guam - Environment, Wildlife, and Snakes

And then there are the snakes.

Sometime in the years right after WWII, as military planes were flying in and out of Guam, a species called the brown tree snake hitched a ride from the South Pacific. It grows several feet long and feeds on small mammals, lizards, and birds. On the island, this invasive predator found easy prey. It feasted on Micronesian kingfishers and Mariana fruit doves and rufous fantails; in just a few decades, it ate 10 out of 12 native forest-bird species off the face of the island.

The effects of the snake’s appetite have rippled through Guam’s ecosystem. Without birds to eat them, spiders have flourished. Without birds to spread seeds, forests have thinned. According to   one estimate, the growth of new tree seedlings has declined between 61 to 92 percent.

The military development of Guam has taken out a lot of forest.