Just answered a question relating to penguins, and it got me thinking - what would the consequences be if Penguins were introduced as a species to the Arctic? Another food source for endangered polar bears... Just a thought
When penguins are moved to the northern hemisphere, (e.g. zoos), it doesn't half mess up their breeding season! Takes them a couple of years to get used to the idea that summer and winter are reversed.
And never having encountered any land-based predators in the Antarctic, they'd probably be such easy meat for bears that they'd soon be wiped out.