This island, I believe, had animals transported there. They might've wanted to test out some experiments to have different sorts of animals to adjust to different climates.

Some oldish news..
I heard that the Smoke monster, is probably a 'reflection' in ones self. A few people've been killed when they saw the monster,(possibly because they weren't 'worthy' of the islands gifts) But Locke, who believes in the power of the island, was one to survive the smoke monster...
*shrugs*