Will they ever learn?
When a new species is introduced into an ecosystem the delicate balance of the system is changed forever and more often than not that change is not a positive one.
If you read the underlying study http://goo.gl/LvqYK this was an unintentional introduction. It does however, provide more evidence that when people mess with mother nature the results cannot be accurately predicted. So why do we continue to do this intentionally today?
http://news.discovery.com/animals/spiders-guam-birds-120914.html