Bullfrogs
Bullfrogs are an eastern U.S. export that have become widely invasive and problematic worldwide. The frogs are voracious predators that eat basically anything they can fit in their mouths and (surprise, surprise) spread a deadly fungus to other amphibians.
There are a few factors that have contributed to the worldwide expansion of bullfrogs. First, bullfrogs were transported by people to lots of places outside their native range because of their one-time popularity as pets and school project animals, not to mention their tasty legs. Then, bullfrogs revealed they were more than capable of moving themselves long distances as well. The frogs, which are routinely larger than a hefty hamburger, can leap up to 6 feet in a single hop and can travel more a mile between isolated waterways over land.
Now, climate change is furthering their spread in some regions by making more habitats bullfrog-friendly. In South America, bullfrogs are projected to move into new areas as the climate warms. In South Korea, under the worst-case climate change scenarios, American bullfrogs are projected to increase their range. In western Canada, climate change is also thought to be facilitating the bullfrog takeover.
