Today in the Sixth Extinction
By This “odd animal sighting” could be bad news for Hawaii’s native wildlife: a five-foot long boa contrictor recently ended up as roadkill along Hawaii’s Pali Highway.
The thing that makes this odd is that it should be impossible to run over a snake in Hawaii, because there aren’t supposed to be any snakes there. As an isolated archipelago, the only way for wildlife species to get to the Hawaiian Islands is to fly or swim across the Pacific Ocean.
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As a result, most of Hawaii’s native wildlife are birds, insects, and marine mammals. It has taken them hundreds of thousands of years to establish populations, evolve together, and create a balanced ecosystem. There is only one non-marine mammal native to Hawaii, the Hawaiian hoary bat. It is both endemic (found no where else on the planet) and endangered. There are no native snakes in Hawaii.
This makes native Hawaiian species in this once-isolated ecosystem extremely vulnearable to species from other parts of the world, particularly predatory species such as snakes, because they have no natural defense against them.
When such invasive exotic species are introduced by human activity–which is now happening in Hawaii at a rate thousands of times faster than it would otherwise naturally–native Hawaiian animals found nowhere else on the planet start going extinct.