March 28, 2009

Trees may be to blame for snake’s decline

The broad-headed snake, found only in the Sydney area, has become the rarest venomous snake in Australia because of too many trees, an expert says.

The snake, classified as endangered by New South Wales, is now found only in isolated populations within 100 miles or so of Sydney.

Rick Shine, a professor at the University of Sydney, told The Sydney Morning Herald he and other researchers compared photographs of Morton National Park south of Sydney from the 1940s and the 1970s with modern satellite photographs. What they discovered is that there are far more trees in the park.

That creates problems for the broad-headed snake, which spends much of its life on sandstone rocks.

They will spend several weeks curled up, moving very little, Shine said. They just sit and wait for velvet geckos.

But shade from trees keeps the rocks cool, too cool for the cold-blooded snakes.

Shine said the snake may become extinct unless the forests are made less dense through controlled burning or selective cutting. He said the end of aboriginal burning may be responsible for the tree explosion.