deadly brown tree snake preys on both eggs and adult birds
habitats are among the world's most fragile ecosystems - home
to unique species that have evolved over millions of years
to meet the requirements of their isolated surroundings. But
in today's global economy, keeping island species protected
from the outside world is a nearly impossible task. On the
South Pacific island of Guam, one alien invader has wrought
unimaginable havoc on native bird life, forcing scientists
to seek radical measures to bring the crisis under control.
on Guam evolved with few natural predators. But in the 1940's,
when the island was an important military hub during and after
the war, some brown tree snakes hitched a ride from a neighboring
island. With no predators of their own, these powerful hunters
began to systematically wipe out Guam's bird life. Today,
Guam is infested with 1 or 2 million snakes, and has lost
all three of its native bird species. Six other regional species
are gone; three are just hanging on. Other islands, like Hawaii,
could be next.
Alan gets close to the Guam rail, now thriving in captivity
but extinct in the wild.
the National Zoo in Washington, biologist Don
Nichols is working on a solution to this ecological disaster.
He has developed a special virus unique to snakes that kills
by flooding their lungs with fluid. The hope is that the highly
contagious virus will spread rapidly among the brown tree
snakes on Guam, without evolving to infect the island's other
reptilian life. For an animal lover like Nichols, it's a tough
situation, but clearly the best way to preserve the environment
in the long run.
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