Iodine is needed by animals because the body's metabolic rate is controlled by the action of an iodine hormone, called thyroxine, which is secreted by the thyroid gland in the neck.
If the animal fails to supply enough iodine through food to be able to make a normal amount of this compound, then the thyroid gland enlarges or expands trying to create enough, resulting in a common type of goiter.
They would freeze and it would be hard to find food because they are not accustomed to the different climate. They would also be easy prey because of the environment change they are not equipped for.
