Answer:
The role that the cane toad play in the Hawaiian Islands is "invasive species"
Explanation:
The excerpt describes the process of how the cane toad was introduced to the Hawaiian Islands, as a new species in this land and to control pests, it also mentions that by not having many predators the number of cane toads grows rapidly, this two points are clear examples of what represents an invasive species which come from a different land and grows excessively in a new one becoming a new threat to the environment. As the name of the kind of role they played shows, they invaded the Hawaiian lands.
