It's not a place I'd recommend visiting. Even if you managed to avoid the guano, you wouldn't escape the snakes.
Tiger snakes, to be precise.
On this tiny island, gulls nest and tiger snakes eat the nestlings. But the gulls fight back. They stab out the snakes' eyes. How's that for heroic?
[In case the links break, a google search including seagulls, tiger snakes, carnac island, brings up interesting results]