#17 How'd that get there?

Invasive species: let's talk about human blunders that led to changing ecosystems, both accidental and intentional cases. Did the building of massive shipping canals connecting seas and oceans allow foreign fish to migrate through them and wreak havoc in their new home? Then to brighten the episode up we discuss some wild migrations that happen naturally, without human intervention. How do birds know where to go? How far will a cute artic fox travel solo? And how can we track migrations and populations to better monitor the disaster/better understand the natural world?